cpython-lru_cache-weakref: Lib/functools.py annotate

annotate Lib/functools.py @ 87690:66c1c9f32567 default tip

Add use_weakref option to functools.lru_cache The use_weakref option makes lru_cache create weak references to the function arguments when creating the cache key, which prevents them from staying in the memory forever even after all other references to them are gone. This is a proof of concept for http://bugs.python.org/issue19859

author	Radomir Dopieralski <devel@sheep.art.pl>
date	Tue, 03 Dec 2013 16:02:48 +0100
parents	ac1685661b07
children

rev	line source
38673 a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	1 """functools.py - Tools for working with functions and callable objects
38669 19fd6141940d Partially merge trunk into p3yk. The removal of Mac/Tools is confusing svn Thomas Wouters <thomas@python.org> parents: diff changeset	2 """
19fd6141940d Partially merge trunk into p3yk. The removal of Mac/Tools is confusing svn Thomas Wouters <thomas@python.org> parents: diff changeset	3 # Python module wrapper for _functools C module
19fd6141940d Partially merge trunk into p3yk. The removal of Mac/Tools is confusing svn Thomas Wouters <thomas@python.org> parents: diff changeset	4 # to allow utilities written in Python to be added
19fd6141940d Partially merge trunk into p3yk. The removal of Mac/Tools is confusing svn Thomas Wouters <thomas@python.org> parents: diff changeset	5 # to the functools module.
84039 dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	6 # Written by Nick Coghlan <ncoghlan at gmail.com>,
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	7 # Raymond Hettinger <python at rcn.com>,
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	8 # and Łukasz Langa <lukasz at langa.pl>.
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	9 # Copyright (C) 2006-2013 Python Software Foundation.
38673 a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	10 # See C source code for _functools credits/copyright
38669 19fd6141940d Partially merge trunk into p3yk. The removal of Mac/Tools is confusing svn Thomas Wouters <thomas@python.org> parents: diff changeset	11
63370 c55876a6fa3c Re-commit r83327 now that the release is done. Georg Brandl <georg@python.org> parents: 63357 diff changeset	12 __all__ = ['update_wrapper', 'wraps', 'WRAPPER_ASSIGNMENTS', 'WRAPPER_UPDATES',
84039 dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	13 'total_ordering', 'cmp_to_key', 'lru_cache', 'reduce', 'partial',
86921 ac1685661b07 Fix functools.partialmethod docs and __all__ Nick Coghlan <ncoghlan@gmail.com> parents: 86867 diff changeset	14 'partialmethod', 'singledispatch']
63370 c55876a6fa3c Re-commit r83327 now that the release is done. Georg Brandl <georg@python.org> parents: 63357 diff changeset	15
80421 fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	16 try:
fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	17 from _functools import reduce
84442 7769c4d72806 Issue #18200: Back out usage of ModuleNotFoundError (8d28d44f3a9a) Brett Cannon <brett@python.org> parents: 84411 diff changeset	18 except ImportError:
80421 fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	19 pass
84039 dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	20 from abc import get_cache_token
75729 3b2856d8614b Improve the memory utilization (and speed) of functools.lru_cache(). Raymond Hettinger <python@rcn.com> parents: 73943 diff changeset	21 from collections import namedtuple
86867 46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	22 from types import MappingProxyType, MethodType
84039 dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	23 from weakref import WeakKeyDictionary
64016 d8d0abe61e83 Add locks to make the caches well behaved in multi-threaded code. Raymond Hettinger <python@rcn.com> parents: 63823 diff changeset	24 try:
82437 1920422626a5 Don't deadlock on a reentrant call. Raymond Hettinger <python@rcn.com> parents: 77336 diff changeset	25 from _thread import RLock
64016 d8d0abe61e83 Add locks to make the caches well behaved in multi-threaded code. Raymond Hettinger <python@rcn.com> parents: 63823 diff changeset	26 except:
82450 e9732c25a018 Remove dependency on dummy_threading (to solve a bootstrap problem). Raymond Hettinger <python@rcn.com> parents: 82437 diff changeset	27 class RLock:
82558 1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	28 'Dummy reentrant lock for builds without threads'
82450 e9732c25a018 Remove dependency on dummy_threading (to solve a bootstrap problem). Raymond Hettinger <python@rcn.com> parents: 82437 diff changeset	29 def __enter__(self): pass
e9732c25a018 Remove dependency on dummy_threading (to solve a bootstrap problem). Raymond Hettinger <python@rcn.com> parents: 82437 diff changeset	30 def __exit__(self, exctype, excinst, exctb): pass
38673 a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	31
75776 66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	32
66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	33 ################################################################################
66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	34 ### update_wrapper() and wraps() decorator
66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	35 ################################################################################
66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	36
38673 a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	37 # update_wrapper() and wraps() are tools to help write
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	38 # wrapper functions that can handle naive introspection
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	39
73943 963e98f5ad31 Issue #13544: Add __qualname__ to functools.WRAPPER_ASSIGNMENTS. Meador Inge <meadori@gmail.com> parents: 73019 diff changeset	40 WRAPPER_ASSIGNMENTS = ('__module__', '__name__', '__qualname__', '__doc__',
963e98f5ad31 Issue #13544: Add __qualname__ to functools.WRAPPER_ASSIGNMENTS. Meador Inge <meadori@gmail.com> parents: 73019 diff changeset	41 '__annotations__')
38673 a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	42 WRAPPER_UPDATES = ('__dict__',)
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	43 def update_wrapper(wrapper,
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	44 wrapped,
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	45 assigned = WRAPPER_ASSIGNMENTS,
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	46 updated = WRAPPER_UPDATES):
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	47 """Update a wrapper function to look like the wrapped function
38669 19fd6141940d Partially merge trunk into p3yk. The removal of Mac/Tools is confusing svn Thomas Wouters <thomas@python.org> parents: diff changeset	48
38673 a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	49 wrapper is the function to be updated
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	50 wrapped is the original function
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	51 assigned is a tuple naming the attributes assigned directly
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	52 from the wrapped function to the wrapper function (defaults to
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	53 functools.WRAPPER_ASSIGNMENTS)
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 39691 diff changeset	54 updated is a tuple naming the attributes of the wrapper that
38673 a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	55 are updated with the corresponding attribute from the wrapped
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	56 function (defaults to functools.WRAPPER_UPDATES)
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	57 """
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	58 for attr in assigned:
64102 77bf58296c87 Document and test the resolution of issue 3445 (tolerate missing attributes in functools.update_wrapper, previously implemented as a side effect of the __annotations__ copying patch) and implement issue 9567 (add a __wrapped__ attribute when using update_wrapper) Nick Coghlan <ncoghlan@gmail.com> parents: 64030 diff changeset	59 try:
77bf58296c87 Document and test the resolution of issue 3445 (tolerate missing attributes in functools.update_wrapper, previously implemented as a side effect of the __annotations__ copying patch) and implement issue 9567 (add a __wrapped__ attribute when using update_wrapper) Nick Coghlan <ncoghlan@gmail.com> parents: 64030 diff changeset	60 value = getattr(wrapped, attr)
77bf58296c87 Document and test the resolution of issue 3445 (tolerate missing attributes in functools.update_wrapper, previously implemented as a side effect of the __annotations__ copying patch) and implement issue 9567 (add a __wrapped__ attribute when using update_wrapper) Nick Coghlan <ncoghlan@gmail.com> parents: 64030 diff changeset	61 except AttributeError:
77bf58296c87 Document and test the resolution of issue 3445 (tolerate missing attributes in functools.update_wrapper, previously implemented as a side effect of the __annotations__ copying patch) and implement issue 9567 (add a __wrapped__ attribute when using update_wrapper) Nick Coghlan <ncoghlan@gmail.com> parents: 64030 diff changeset	62 pass
77bf58296c87 Document and test the resolution of issue 3445 (tolerate missing attributes in functools.update_wrapper, previously implemented as a side effect of the __annotations__ copying patch) and implement issue 9567 (add a __wrapped__ attribute when using update_wrapper) Nick Coghlan <ncoghlan@gmail.com> parents: 64030 diff changeset	63 else:
77bf58296c87 Document and test the resolution of issue 3445 (tolerate missing attributes in functools.update_wrapper, previously implemented as a side effect of the __annotations__ copying patch) and implement issue 9567 (add a __wrapped__ attribute when using update_wrapper) Nick Coghlan <ncoghlan@gmail.com> parents: 64030 diff changeset	64 setattr(wrapper, attr, value)
38673 a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	65 for attr in updated:
40450 cc992d75d5b3 Four months of trunk changes (including a few releases...) Thomas Wouters <thomas@python.org> parents: 39691 diff changeset	66 getattr(wrapper, attr).update(getattr(wrapped, attr, {}))
84629 13b8fd71db46 Close issue 17482: don't overwrite __wrapped__ Nick Coghlan <ncoghlan@gmail.com> parents: 84442 diff changeset	67 # Issue #17482: set __wrapped__ last so we don't inadvertently copy it
13b8fd71db46 Close issue 17482: don't overwrite __wrapped__ Nick Coghlan <ncoghlan@gmail.com> parents: 84442 diff changeset	68 # from the wrapped function when updating __dict__
13b8fd71db46 Close issue 17482: don't overwrite __wrapped__ Nick Coghlan <ncoghlan@gmail.com> parents: 84442 diff changeset	69 wrapper.__wrapped__ = wrapped
38673 a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	70 # Return the wrapper so this can be used as a decorator via partial()
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	71 return wrapper
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	72
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	73 def wraps(wrapped,
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	74 assigned = WRAPPER_ASSIGNMENTS,
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	75 updated = WRAPPER_UPDATES):
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	76 """Decorator factory to apply update_wrapper() to a wrapper function
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	77
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	78 Returns a decorator that invokes update_wrapper() with the decorated
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	79 function as the wrapper argument and the arguments to wraps() as the
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	80 remaining arguments. Default arguments are as for update_wrapper().
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	81 This is a convenience function to simplify applying partial() to
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	82 update_wrapper().
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	83 """
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	84 return partial(update_wrapper, wrapped=wrapped,
a19c20c5e5c7 Merge the rest of the trunk. Thomas Wouters <thomas@python.org> parents: 38669 diff changeset	85 assigned=assigned, updated=updated)
60370 3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	86
75776 66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	87
66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	88 ################################################################################
66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	89 ### total_ordering class decorator
66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	90 ################################################################################
66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	91
85913 ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	92 # The correct way to indicate that a comparison operation doesn't
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	93 # recognise the other type is to return NotImplemented and let the
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	94 # interpreter handle raising TypeError if both operands return
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	95 # NotImplemented from their respective comparison methods
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	96 #
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	97 # This makes the implementation of total_ordering more complicated, since
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	98 # we need to be careful not to trigger infinite recursion when two
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	99 # different types that both use this decorator encounter each other.
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	100 #
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	101 # For example, if a type implements __lt__, it's natural to define
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	102 # __gt__ as something like:
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	103 #
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	104 # lambda self, other: not self < other and not self == other
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	105 #
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	106 # However, using the operator syntax like that ends up invoking the full
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	107 # type checking machinery again and means we can end up bouncing back and
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	108 # forth between the two operands until we run out of stack space.
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	109 #
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	110 # The solution is to define helper functions that invoke the appropriate
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	111 # magic methods directly, ensuring we only try each operand once, and
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	112 # return NotImplemented immediately if it is returned from the
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	113 # underlying user provided method. Using this scheme, the __gt__ derived
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	114 # from a user provided __lt__ becomes:
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	115 #
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	116 # lambda self, other: _not_op_and_not_eq(self.__lt__, self, other))
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	117
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	118 def _not_op(op, other):
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	119 # "not a < b" handles "a >= b"
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	120 # "not a <= b" handles "a > b"
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	121 # "not a >= b" handles "a < b"
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	122 # "not a > b" handles "a <= b"
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	123 op_result = op(other)
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	124 if op_result is NotImplemented:
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	125 return NotImplemented
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	126 return not op_result
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	127
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	128 def _op_or_eq(op, self, other):
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	129 # "a < b or a == b" handles "a <= b"
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	130 # "a > b or a == b" handles "a >= b"
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	131 op_result = op(other)
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	132 if op_result is NotImplemented:
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	133 return NotImplemented
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	134 return op_result or self == other
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	135
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	136 def _not_op_and_not_eq(op, self, other):
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	137 # "not (a < b or a == b)" handles "a > b"
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	138 # "not a < b and a != b" is equivalent
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	139 # "not (a > b or a == b)" handles "a < b"
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	140 # "not a > b and a != b" is equivalent
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	141 op_result = op(other)
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	142 if op_result is NotImplemented:
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	143 return NotImplemented
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	144 return not op_result and self != other
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	145
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	146 def _not_op_or_eq(op, self, other):
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	147 # "not a <= b or a == b" handles "a >= b"
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	148 # "not a >= b or a == b" handles "a <= b"
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	149 op_result = op(other)
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	150 if op_result is NotImplemented:
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	151 return NotImplemented
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	152 return not op_result or self == other
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	153
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	154 def _op_and_not_eq(op, self, other):
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	155 # "a <= b and not a == b" handles "a < b"
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	156 # "a >= b and not a == b" handles "a > b"
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	157 op_result = op(other)
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	158 if op_result is NotImplemented:
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	159 return NotImplemented
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	160 return op_result and self != other
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	161
60370 3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	162 def total_ordering(cls):
61761 82a4483d9c4a Merged revisions 80068 via svnmerge from Georg Brandl <georg@python.org> parents: 60479 diff changeset	163 """Class decorator that fills in missing ordering methods"""
60370 3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	164 convert = {
85913 ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	165 '__lt__': [('__gt__', lambda self, other: _not_op_and_not_eq(self.__lt__, self, other)),
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	166 ('__le__', lambda self, other: _op_or_eq(self.__lt__, self, other)),
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	167 ('__ge__', lambda self, other: _not_op(self.__lt__, other))],
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	168 '__le__': [('__ge__', lambda self, other: _not_op_or_eq(self.__le__, self, other)),
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	169 ('__lt__', lambda self, other: _op_and_not_eq(self.__le__, self, other)),
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	170 ('__gt__', lambda self, other: _not_op(self.__le__, other))],
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	171 '__gt__': [('__lt__', lambda self, other: _not_op_and_not_eq(self.__gt__, self, other)),
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	172 ('__ge__', lambda self, other: _op_or_eq(self.__gt__, self, other)),
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	173 ('__le__', lambda self, other: _not_op(self.__gt__, other))],
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	174 '__ge__': [('__le__', lambda self, other: _not_op_or_eq(self.__ge__, self, other)),
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	175 ('__gt__', lambda self, other: _op_and_not_eq(self.__ge__, self, other)),
ad9f207645ab Close #10042: functools.total_ordering now handles NotImplemented Nick Coghlan <ncoghlan@gmail.com> parents: 84629 diff changeset	176 ('__lt__', lambda self, other: _not_op(self.__ge__, other))]
60370 3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	177 }
64776 985072cd31d0 Improve comment Raymond Hettinger <python@rcn.com> parents: 64755 diff changeset	178 # Find user-defined comparisons (not those inherited from object).
64755 f643d53c51bd Future proof total_ordering against changes in methods defined on object. Raymond Hettinger <python@rcn.com> parents: 64642 diff changeset	179 roots = [op for op in convert if getattr(cls, op, None) is not getattr(object, op, None)]
60479 805512329c75 Issue 8361: Remove assert from functools.total_ordering Raymond Hettinger <python@rcn.com> parents: 60370 diff changeset	180 if not roots:
805512329c75 Issue 8361: Remove assert from functools.total_ordering Raymond Hettinger <python@rcn.com> parents: 60370 diff changeset	181 raise ValueError('must define at least one ordering operation: < > <= >=')
805512329c75 Issue 8361: Remove assert from functools.total_ordering Raymond Hettinger <python@rcn.com> parents: 60370 diff changeset	182 root = max(roots) # prefer __lt__ to __le__ to __gt__ to __ge__
60370 3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	183 for opname, opfunc in convert[root]:
3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	184 if opname not in roots:
3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	185 opfunc.__name__ = opname
3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	186 opfunc.__doc__ = getattr(int, opname).__doc__
3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	187 setattr(cls, opname, opfunc)
3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	188 return cls
3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	189
75776 66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	190
66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	191 ################################################################################
66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	192 ### cmp_to_key() function converter
66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	193 ################################################################################
66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	194
60370 3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	195 def cmp_to_key(mycmp):
61761 82a4483d9c4a Merged revisions 80068 via svnmerge from Georg Brandl <georg@python.org> parents: 60479 diff changeset	196 """Convert a cmp= function into a key= function"""
60370 3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	197 class K(object):
68824 97799a54728e Issue #11628: cmp_to_key should use __slots__. Raymond Hettinger <python@rcn.com> parents: 68257 diff changeset	198 __slots__ = ['obj']
69862 9f58612bc334 Sync-up minor code edits with the default branch. Raymond Hettinger <python@rcn.com> parents: 69810 diff changeset	199 def __init__(self, obj):
60370 3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	200 self.obj = obj
3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	201 def __lt__(self, other):
3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	202 return mycmp(self.obj, other.obj) < 0
3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	203 def __gt__(self, other):
3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	204 return mycmp(self.obj, other.obj) > 0
3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	205 def __eq__(self, other):
3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	206 return mycmp(self.obj, other.obj) == 0
3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	207 def __le__(self, other):
3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	208 return mycmp(self.obj, other.obj) <= 0
3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	209 def __ge__(self, other):
3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	210 return mycmp(self.obj, other.obj) >= 0
3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	211 def __ne__(self, other):
3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	212 return mycmp(self.obj, other.obj) != 0
69810 2675415c57c1 Fix __hash__ in functools.cmp_to_key() to work with collections.Hashable. Raymond Hettinger <python@rcn.com> parents: 68824 diff changeset	213 __hash__ = None
60370 3ce66c6922ab Forward port total_ordering() and cmp_to_key(). Raymond Hettinger <python@rcn.com> parents: 40450 diff changeset	214 return K
63370 c55876a6fa3c Re-commit r83327 now that the release is done. Georg Brandl <georg@python.org> parents: 63357 diff changeset	215
69150 a03fb2fc3ed8 Issue #11707: Fast C version of functools.cmp_to_key() Raymond Hettinger <python@rcn.com> parents: 68825 diff changeset	216 try:
a03fb2fc3ed8 Issue #11707: Fast C version of functools.cmp_to_key() Raymond Hettinger <python@rcn.com> parents: 68825 diff changeset	217 from _functools import cmp_to_key
84442 7769c4d72806 Issue #18200: Back out usage of ModuleNotFoundError (8d28d44f3a9a) Brett Cannon <brett@python.org> parents: 84411 diff changeset	218 except ImportError:
69150 a03fb2fc3ed8 Issue #11707: Fast C version of functools.cmp_to_key() Raymond Hettinger <python@rcn.com> parents: 68825 diff changeset	219 pass
a03fb2fc3ed8 Issue #11707: Fast C version of functools.cmp_to_key() Raymond Hettinger <python@rcn.com> parents: 68825 diff changeset	220
75776 66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	221
66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	222 ################################################################################
80421 fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	223 ### partial() argument application
fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	224 ################################################################################
fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	225
86867 46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	226 # Purely functional, no descriptor behaviour
80421 fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	227 def partial(func, args, *keywords):
86867 46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	228 """New function with partial application of the given arguments
80421 fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	229 and keywords.
fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	230 """
fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	231 def newfunc(fargs, *fkeywords):
fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	232 newkeywords = keywords.copy()
fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	233 newkeywords.update(fkeywords)
fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	234 return func((args + fargs), *newkeywords)
fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	235 newfunc.func = func
fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	236 newfunc.args = args
fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	237 newfunc.keywords = keywords
fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	238 return newfunc
fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	239
fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	240 try:
fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	241 from _functools import partial
84442 7769c4d72806 Issue #18200: Back out usage of ModuleNotFoundError (8d28d44f3a9a) Brett Cannon <brett@python.org> parents: 84411 diff changeset	242 except ImportError:
80421 fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	243 pass
fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	244
86867 46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	245 # Descriptor version
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	246 class partialmethod(object):
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	247 """Method descriptor with partial application of the given arguments
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	248 and keywords.
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	249
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	250 Supports wrapping existing descriptors and handles non-descriptor
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	251 callables as instance methods.
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	252 """
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	253
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	254 def __init__(self, func, args, *keywords):
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	255 if not callable(func) and not hasattr(func, "__get__"):
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	256 raise TypeError("{!r} is not callable or a descriptor"
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	257 .format(func))
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	258
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	259 # func could be a descriptor like classmethod which isn't callable,
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	260 # so we can't inherit from partial (it verifies func is callable)
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	261 if isinstance(func, partialmethod):
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	262 # flattening is mandatory in order to place cls/self before all
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	263 # other arguments
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	264 # it's also more efficient since only one function will be called
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	265 self.func = func.func
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	266 self.args = func.args + args
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	267 self.keywords = func.keywords.copy()
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	268 self.keywords.update(keywords)
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	269 else:
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	270 self.func = func
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	271 self.args = args
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	272 self.keywords = keywords
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	273
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	274 def __repr__(self):
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	275 args = ", ".join(map(repr, self.args))
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	276 keywords = ", ".join("{}={!r}".format(k, v)
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	277 for k, v in self.keywords.items())
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	278 format_string = "{module}.{cls}({func}, {args}, {keywords})"
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	279 return format_string.format(module=self.__class__.__module__,
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	280 cls=self.__class__.__name__,
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	281 func=self.func,
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	282 args=args,
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	283 keywords=keywords)
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	284
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	285 def _make_unbound_method(self):
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	286 def _method(args, *keywords):
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	287 call_keywords = self.keywords.copy()
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	288 call_keywords.update(keywords)
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	289 cls_or_self, *rest = args
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	290 call_args = (cls_or_self,) + self.args + tuple(rest)
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	291 return self.func(call_args, *call_keywords)
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	292 _method.__isabstractmethod__ = self.__isabstractmethod__
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	293 return _method
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	294
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	295 def __get__(self, obj, cls):
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	296 get = getattr(self.func, "__get__", None)
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	297 result = None
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	298 if get is not None:
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	299 new_func = get(obj, cls)
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	300 if new_func is not self.func:
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	301 # Assume __get__ returning something new indicates the
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	302 # creation of an appropriate callable
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	303 result = partial(new_func, self.args, *self.keywords)
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	304 try:
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	305 result.__self__ = new_func.__self__
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	306 except AttributeError:
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	307 pass
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	308 if result is None:
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	309 # If the underlying descriptor didn't do anything, treat this
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	310 # like an instance method
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	311 result = self._make_unbound_method().__get__(obj, cls)
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	312 return result
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	313
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	314 @property
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	315 def __isabstractmethod__(self):
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	316 return getattr(self.func, "__isabstractmethod__", False)
46d3c5539981 Issue #4331: Added functools.partialmethod Nick Coghlan <ncoghlan@gmail.com> parents: 85913 diff changeset	317
80421 fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	318
fcfaca024160 Issue #12428: Add a pure Python implementation of functools.partial(). Antoine Pitrou <solipsis@pitrou.net> parents: 77336 diff changeset	319 ################################################################################
75776 66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	320 ### LRU Cache function decorator
66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	321 ################################################################################
66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	322
75775 70672d21b9fd Minor beautification. Raymond Hettinger <python@rcn.com> parents: 75760 diff changeset	323 _CacheInfo = namedtuple("CacheInfo", ["hits", "misses", "maxsize", "currsize"])
66550 312b2916cfd4 Issue 10586: change the new functools.lru_cache implementation to expose the maximum and current cache sizes through the public statistics API. This API is now a single function that returns a named tuple. Nick Coghlan <ncoghlan@gmail.com> parents: 66441 diff changeset	324
77336 2d5ca0ea2aab Separate key creation logic from the sequence class that memoizes its hash value. Raymond Hettinger <python@rcn.com> parents: 77068 diff changeset	325 class _HashedSeq(list):
82558 1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	326 """ This class guarantees that hash() will be called no more than once
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	327 per element. This is important because the lru_cache() will hash
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	328 the key multiple times on a cache miss.
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	329
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	330 """
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	331
76681 f981fe3b8bf7 Move make_key() out of the decorator body. Make keys that only need to be hashed once. Raymond Hettinger <python@rcn.com> parents: 76680 diff changeset	332 __slots__ = 'hashvalue'
f981fe3b8bf7 Move make_key() out of the decorator body. Make keys that only need to be hashed once. Raymond Hettinger <python@rcn.com> parents: 76680 diff changeset	333
77336 2d5ca0ea2aab Separate key creation logic from the sequence class that memoizes its hash value. Raymond Hettinger <python@rcn.com> parents: 77068 diff changeset	334 def __init__(self, tup, hash=hash):
2d5ca0ea2aab Separate key creation logic from the sequence class that memoizes its hash value. Raymond Hettinger <python@rcn.com> parents: 77068 diff changeset	335 self[:] = tup
2d5ca0ea2aab Separate key creation logic from the sequence class that memoizes its hash value. Raymond Hettinger <python@rcn.com> parents: 77068 diff changeset	336 self.hashvalue = hash(tup)
76681 f981fe3b8bf7 Move make_key() out of the decorator body. Make keys that only need to be hashed once. Raymond Hettinger <python@rcn.com> parents: 76680 diff changeset	337
f981fe3b8bf7 Move make_key() out of the decorator body. Make keys that only need to be hashed once. Raymond Hettinger <python@rcn.com> parents: 76680 diff changeset	338 def __hash__(self):
f981fe3b8bf7 Move make_key() out of the decorator body. Make keys that only need to be hashed once. Raymond Hettinger <python@rcn.com> parents: 76680 diff changeset	339 return self.hashvalue
f981fe3b8bf7 Move make_key() out of the decorator body. Make keys that only need to be hashed once. Raymond Hettinger <python@rcn.com> parents: 76680 diff changeset	340
87690 66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	341 def _weaken(arg, callback=None):
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	342 """Try to make weak reference. Return the original object if it fails."""
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	343 try:
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	344 return weakref.ref(arg, callback)
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	345 except TypeError:
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	346 return arg
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	347
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	348 def _make_key(args, kwds, typed, remove_key=None,
77336 2d5ca0ea2aab Separate key creation logic from the sequence class that memoizes its hash value. Raymond Hettinger <python@rcn.com> parents: 77068 diff changeset	349 kwd_mark = (object(),),
2d5ca0ea2aab Separate key creation logic from the sequence class that memoizes its hash value. Raymond Hettinger <python@rcn.com> parents: 77068 diff changeset	350 fasttypes = {int, str, frozenset, type(None)},
2d5ca0ea2aab Separate key creation logic from the sequence class that memoizes its hash value. Raymond Hettinger <python@rcn.com> parents: 77068 diff changeset	351 sorted=sorted, tuple=tuple, type=type, len=len):
82558 1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	352 """Make a cache key from optionally typed positional and keyword arguments
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	353
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	354 The key is constructed in a way that is flat as possible rather than
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	355 as a nested structure that would take more memory.
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	356
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	357 If there is only a single argument and its data type is known to cache
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	358 its hash value, then that argument is returned without a wrapper. This
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	359 saves space and improves lookup speed.
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	360
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	361 """
77336 2d5ca0ea2aab Separate key creation logic from the sequence class that memoizes its hash value. Raymond Hettinger <python@rcn.com> parents: 77068 diff changeset	362 key = args
2d5ca0ea2aab Separate key creation logic from the sequence class that memoizes its hash value. Raymond Hettinger <python@rcn.com> parents: 77068 diff changeset	363 if kwds:
2d5ca0ea2aab Separate key creation logic from the sequence class that memoizes its hash value. Raymond Hettinger <python@rcn.com> parents: 77068 diff changeset	364 sorted_items = sorted(kwds.items())
2d5ca0ea2aab Separate key creation logic from the sequence class that memoizes its hash value. Raymond Hettinger <python@rcn.com> parents: 77068 diff changeset	365 key += kwd_mark
2d5ca0ea2aab Separate key creation logic from the sequence class that memoizes its hash value. Raymond Hettinger <python@rcn.com> parents: 77068 diff changeset	366 for item in sorted_items:
2d5ca0ea2aab Separate key creation logic from the sequence class that memoizes its hash value. Raymond Hettinger <python@rcn.com> parents: 77068 diff changeset	367 key += item
2d5ca0ea2aab Separate key creation logic from the sequence class that memoizes its hash value. Raymond Hettinger <python@rcn.com> parents: 77068 diff changeset	368 if typed:
2d5ca0ea2aab Separate key creation logic from the sequence class that memoizes its hash value. Raymond Hettinger <python@rcn.com> parents: 77068 diff changeset	369 key += tuple(type(v) for v in args)
2d5ca0ea2aab Separate key creation logic from the sequence class that memoizes its hash value. Raymond Hettinger <python@rcn.com> parents: 77068 diff changeset	370 if kwds:
2d5ca0ea2aab Separate key creation logic from the sequence class that memoizes its hash value. Raymond Hettinger <python@rcn.com> parents: 77068 diff changeset	371 key += tuple(type(v) for k, v in sorted_items)
2d5ca0ea2aab Separate key creation logic from the sequence class that memoizes its hash value. Raymond Hettinger <python@rcn.com> parents: 77068 diff changeset	372 elif len(key) == 1 and type(key[0]) in fasttypes:
2d5ca0ea2aab Separate key creation logic from the sequence class that memoizes its hash value. Raymond Hettinger <python@rcn.com> parents: 77068 diff changeset	373 return key[0]
2d5ca0ea2aab Separate key creation logic from the sequence class that memoizes its hash value. Raymond Hettinger <python@rcn.com> parents: 77068 diff changeset	374 return _HashedSeq(key)
2d5ca0ea2aab Separate key creation logic from the sequence class that memoizes its hash value. Raymond Hettinger <python@rcn.com> parents: 77068 diff changeset	375
87690 66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	376 def _make_weakref_key(args, kwds, typed, remove_key,
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	377 kwd_mark = (object(),),
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	378 fasttypes= {int, str, frozenset, type(None)},
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	379 sorted=sorted, tuple=tuple, type=type, len=len):
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	380 """Like ``_make_key``, but use weak references to arguments.
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	381
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	382 The function ``remove_key`` will be called back with a key when any of that
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	383 key's arguments no longer has any references.
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	384
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	385 This function duplicates some code from ``_make_key`` for performance
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	386 reasons, to avoid additional checks and function calls in the original
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	387 function.
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	388 """
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	389 key = None
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	390
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	391 def weakref_callback(ref):
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	392 # The key here is stored in a closure, because we need this callback
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	393 # before we have the key, as it is used in the weakrefs for the key.
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	394 remove_key(key)
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	395
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	396 key = tuple(_weaken(arg, weakref_callback) for arg in args)
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	397 if kwds:
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	398 sorted_items = sorted(kwds.items())
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	399 key += kwd_mark
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	400 for key, value in sorted_items:
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	401 key += key, _weaken(value, weakref_callback)
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	402 if typed:
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	403 key += tuple(type(v) for v in args)
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	404 if kwds:
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	405 key += tuple(type(v) for k, v in sorted_items)
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	406 elif len(key) == 1 and type(key[0]) in fasttypes:
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	407 return key[0]
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	408 return _HashedSeq(key)
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	409
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	410 def lru_cache(maxsize=128, typed=False, use_weakref=False):
63823 1086dad50c74 use same quoting as the rest of the file Benjamin Peterson <benjamin@python.org> parents: 63745 diff changeset	411 """Least-recently-used cache decorator.
63370 c55876a6fa3c Re-commit r83327 now that the release is done. Georg Brandl <georg@python.org> parents: 63357 diff changeset	412
66582 00c8cdf53936 Issue 10593: Adopt Nick's suggestion for an lru_cache with maxsize=None. Raymond Hettinger <python@rcn.com> parents: 66578 diff changeset	413 If maxsize is set to None, the LRU features are disabled and the cache
00c8cdf53936 Issue 10593: Adopt Nick's suggestion for an lru_cache with maxsize=None. Raymond Hettinger <python@rcn.com> parents: 66578 diff changeset	414 can grow without bound.
00c8cdf53936 Issue 10593: Adopt Nick's suggestion for an lru_cache with maxsize=None. Raymond Hettinger <python@rcn.com> parents: 66578 diff changeset	415
73019 cba503a2c468 Issue 13227: Option to make the lru_cache() type specific (suggested by Andrew Koenig). Raymond Hettinger <python@rcn.com> parents: 72944 diff changeset	416 If typed is True, arguments of different types will be cached separately.
cba503a2c468 Issue 13227: Option to make the lru_cache() type specific (suggested by Andrew Koenig). Raymond Hettinger <python@rcn.com> parents: 72944 diff changeset	417 For example, f(3.0) and f(3) will be treated as distinct calls with
cba503a2c468 Issue 13227: Option to make the lru_cache() type specific (suggested by Andrew Koenig). Raymond Hettinger <python@rcn.com> parents: 72944 diff changeset	418 distinct results.
cba503a2c468 Issue 13227: Option to make the lru_cache() type specific (suggested by Andrew Koenig). Raymond Hettinger <python@rcn.com> parents: 72944 diff changeset	419
87690 66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	420 If use_weakref is True, the cache will not keep references to the
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	421 arguments, keeping them alive in memory forever. Instead, cache entries
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	422 related to objects that are no longer used will be automatically removed
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	423 from cache.
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	424
63370 c55876a6fa3c Re-commit r83327 now that the release is done. Georg Brandl <georg@python.org> parents: 63357 diff changeset	425 Arguments to the cached function must be hashable.
66441 03d933948bf3 Clean-up docstring, comments, and whitespace. Raymond Hettinger <python@rcn.com> parents: 64776 diff changeset	426
76003 387dcd8d7dec Fix-up comments and add a sentinel variable for clarity. Raymond Hettinger <python@rcn.com> parents: 76002 diff changeset	427 View the cache statistics named tuple (hits, misses, maxsize, currsize)
387dcd8d7dec Fix-up comments and add a sentinel variable for clarity. Raymond Hettinger <python@rcn.com> parents: 76002 diff changeset	428 with f.cache_info(). Clear the cache and statistics with f.cache_clear().
66578 5cb53f094c1a Doc and docstring nits. Raymond Hettinger <python@rcn.com> parents: 66573 diff changeset	429 Access the underlying function with f.__wrapped__.
66441 03d933948bf3 Clean-up docstring, comments, and whitespace. Raymond Hettinger <python@rcn.com> parents: 64776 diff changeset	430
03d933948bf3 Clean-up docstring, comments, and whitespace. Raymond Hettinger <python@rcn.com> parents: 64776 diff changeset	431 See: http://en.wikipedia.org/wiki/Cache_algorithms#Least_Recently_Used
63370 c55876a6fa3c Re-commit r83327 now that the release is done. Georg Brandl <georg@python.org> parents: 63357 diff changeset	432
63823 1086dad50c74 use same quoting as the rest of the file Benjamin Peterson <benjamin@python.org> parents: 63745 diff changeset	433 """
75998 123cf2192c79 Minor cleanup: add whitespace, add comments, bring function attribute updates together. Raymond Hettinger <python@rcn.com> parents: 75803 diff changeset	434
66441 03d933948bf3 Clean-up docstring, comments, and whitespace. Raymond Hettinger <python@rcn.com> parents: 64776 diff changeset	435 # Users should only access the lru_cache through its public API:
66552 f16bf4cae5d7 Neaten-up a bit. Raymond Hettinger <python@rcn.com> parents: 66550 diff changeset	436 # cache_info, cache_clear, and f.__wrapped__
66441 03d933948bf3 Clean-up docstring, comments, and whitespace. Raymond Hettinger <python@rcn.com> parents: 64776 diff changeset	437 # The internals of the lru_cache are encapsulated for thread safety and
03d933948bf3 Clean-up docstring, comments, and whitespace. Raymond Hettinger <python@rcn.com> parents: 64776 diff changeset	438 # to allow the implementation to change (including a possible C version).
03d933948bf3 Clean-up docstring, comments, and whitespace. Raymond Hettinger <python@rcn.com> parents: 64776 diff changeset	439
76649 2adcd28a5a3a Factor out shared variables. Raymond Hettinger <python@rcn.com> parents: 76643 diff changeset	440 # Constants shared by all lru cache instances:
76656 d4fd58fff480 Track the cache size directly. Raymond Hettinger <python@rcn.com> parents: 76649 diff changeset	441 sentinel = object() # unique object used to signal cache misses
76649 2adcd28a5a3a Factor out shared variables. Raymond Hettinger <python@rcn.com> parents: 76643 diff changeset	442 PREV, NEXT, KEY, RESULT = 0, 1, 2, 3 # names for the link fields
2adcd28a5a3a Factor out shared variables. Raymond Hettinger <python@rcn.com> parents: 76643 diff changeset	443
87690 66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	444 if use_weakref:
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	445 make_key = _make_weakref_key
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	446 else:
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	447 make_key = _make_key # build a key from the function arguments
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	448
75757 51b0711ee672 Refactor calculation of the cache key. Minor code cleanups. Raymond Hettinger <python@rcn.com> parents: 75753 diff changeset	449 def decorating_function(user_function):
76003 387dcd8d7dec Fix-up comments and add a sentinel variable for clarity. Raymond Hettinger <python@rcn.com> parents: 76002 diff changeset	450 cache = {}
82560 a9fa8a18d18d Sync-up with 3.4 to make maintenance easier. Raymond Hettinger <python@rcn.com> parents: 82558 diff changeset	451 hits = misses = 0
76680 f5bb290c751a Use a flag to indicate when the circular queue is fully populated and stable. Raymond Hettinger <python@rcn.com> parents: 76675 diff changeset	452 full = False
76004 1c22c1109824 Fix-up a comment Raymond Hettinger <python@rcn.com> parents: 76003 diff changeset	453 cache_get = cache.get # bound method to lookup a key or return None
82437 1920422626a5 Don't deadlock on a reentrant call. Raymond Hettinger <python@rcn.com> parents: 77336 diff changeset	454 lock = RLock() # because linkedlist updates aren't threadsafe
76003 387dcd8d7dec Fix-up comments and add a sentinel variable for clarity. Raymond Hettinger <python@rcn.com> parents: 76002 diff changeset	455 root = [] # root of the circular doubly linked list
387dcd8d7dec Fix-up comments and add a sentinel variable for clarity. Raymond Hettinger <python@rcn.com> parents: 76002 diff changeset	456 root[:] = [root, root, None, None] # initialize by pointing to self
87690 66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	457 remove_key = None # only used with use_weakref
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	458
75757 51b0711ee672 Refactor calculation of the cache key. Minor code cleanups. Raymond Hettinger <python@rcn.com> parents: 75753 diff changeset	459
75802 7080f443bd37 Low overhead path for maxsize==0 Raymond Hettinger <python@rcn.com> parents: 75776 diff changeset	460 if maxsize == 0:
7080f443bd37 Low overhead path for maxsize==0 Raymond Hettinger <python@rcn.com> parents: 75776 diff changeset	461
7080f443bd37 Low overhead path for maxsize==0 Raymond Hettinger <python@rcn.com> parents: 75776 diff changeset	462 def wrapper(args, *kwds):
82558 1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	463 # No caching -- just a statistics update after a successful call
75802 7080f443bd37 Low overhead path for maxsize==0 Raymond Hettinger <python@rcn.com> parents: 75776 diff changeset	464 nonlocal misses
75803 b26056192653 Fix whitespace Raymond Hettinger <python@rcn.com> parents: 75802 diff changeset	465 result = user_function(args, *kwds)
75802 7080f443bd37 Low overhead path for maxsize==0 Raymond Hettinger <python@rcn.com> parents: 75776 diff changeset	466 misses += 1
7080f443bd37 Low overhead path for maxsize==0 Raymond Hettinger <python@rcn.com> parents: 75776 diff changeset	467 return result
7080f443bd37 Low overhead path for maxsize==0 Raymond Hettinger <python@rcn.com> parents: 75776 diff changeset	468
7080f443bd37 Low overhead path for maxsize==0 Raymond Hettinger <python@rcn.com> parents: 75776 diff changeset	469 elif maxsize is None:
87690 66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	470 if use_weakref:
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	471
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	472 def remove_key(key):
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	473 # A callback for removing keys from cache
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	474 try:
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	475 del cache[key]
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	476 except KeyError:
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	477 pass
75776 66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	478
66582 00c8cdf53936 Issue 10593: Adopt Nick's suggestion for an lru_cache with maxsize=None. Raymond Hettinger <python@rcn.com> parents: 66578 diff changeset	479 def wrapper(args, *kwds):
82558 1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	480 # Simple caching without ordering or size limit
82560 a9fa8a18d18d Sync-up with 3.4 to make maintenance easier. Raymond Hettinger <python@rcn.com> parents: 82558 diff changeset	481 nonlocal hits, misses
87690 66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	482 key = make_key(args, kwds, typed, remove_key)
76003 387dcd8d7dec Fix-up comments and add a sentinel variable for clarity. Raymond Hettinger <python@rcn.com> parents: 76002 diff changeset	483 result = cache_get(key, sentinel)
387dcd8d7dec Fix-up comments and add a sentinel variable for clarity. Raymond Hettinger <python@rcn.com> parents: 76002 diff changeset	484 if result is not sentinel:
66550 312b2916cfd4 Issue 10586: change the new functools.lru_cache implementation to expose the maximum and current cache sizes through the public statistics API. This API is now a single function that returns a named tuple. Nick Coghlan <ncoghlan@gmail.com> parents: 66441 diff changeset	485 hits += 1
72943 8365f82f8a13 Issue 13177: Make tracebacks more readable by avoiding chained exceptions in the lru_cache. Raymond Hettinger <python@rcn.com> parents: 69862 diff changeset	486 return result
8365f82f8a13 Issue 13177: Make tracebacks more readable by avoiding chained exceptions in the lru_cache. Raymond Hettinger <python@rcn.com> parents: 69862 diff changeset	487 result = user_function(args, *kwds)
8365f82f8a13 Issue 13177: Make tracebacks more readable by avoiding chained exceptions in the lru_cache. Raymond Hettinger <python@rcn.com> parents: 69862 diff changeset	488 cache[key] = result
8365f82f8a13 Issue 13177: Make tracebacks more readable by avoiding chained exceptions in the lru_cache. Raymond Hettinger <python@rcn.com> parents: 69862 diff changeset	489 misses += 1
66582 00c8cdf53936 Issue 10593: Adopt Nick's suggestion for an lru_cache with maxsize=None. Raymond Hettinger <python@rcn.com> parents: 66578 diff changeset	490 return result
75776 66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	491
66582 00c8cdf53936 Issue 10593: Adopt Nick's suggestion for an lru_cache with maxsize=None. Raymond Hettinger <python@rcn.com> parents: 66578 diff changeset	492 else:
87690 66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	493 if use_weakref:
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	494
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	495 def remove_key(key):
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	496 # A callback for removing keys from cache
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	497 with lock:
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	498 link = cache_get(key)
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	499 if link is not None:
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	500 link_prev, link_next, _key, result = link
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	501 link_prev[NEXT] = link_next
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	502 link_next[PREV] = link_prev
66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	503 del cache[key]
75776 66803fd0a6bc Section-off the source for better readability. Raymond Hettinger <python@rcn.com> parents: 75775 diff changeset	504
66582 00c8cdf53936 Issue 10593: Adopt Nick's suggestion for an lru_cache with maxsize=None. Raymond Hettinger <python@rcn.com> parents: 66578 diff changeset	505 def wrapper(args, *kwds):
82558 1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	506 # Size limited caching that tracks accesses by recency
82560 a9fa8a18d18d Sync-up with 3.4 to make maintenance easier. Raymond Hettinger <python@rcn.com> parents: 82558 diff changeset	507 nonlocal root, hits, misses, full
87690 66c1c9f32567 Add use_weakref option to functools.lru_cache Radomir Dopieralski <devel@sheep.art.pl> parents: 86921 diff changeset	508 key = make_key(args, kwds, typed, remove_key)
72943 8365f82f8a13 Issue 13177: Make tracebacks more readable by avoiding chained exceptions in the lru_cache. Raymond Hettinger <python@rcn.com> parents: 69862 diff changeset	509 with lock:
75729 3b2856d8614b Improve the memory utilization (and speed) of functools.lru_cache(). Raymond Hettinger <python@rcn.com> parents: 73943 diff changeset	510 link = cache_get(key)
3b2856d8614b Improve the memory utilization (and speed) of functools.lru_cache(). Raymond Hettinger <python@rcn.com> parents: 73943 diff changeset	511 if link is not None:
82558 1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	512 # Move the link to the front of the circular queue
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	513 link_prev, link_next, _key, result = link
75729 3b2856d8614b Improve the memory utilization (and speed) of functools.lru_cache(). Raymond Hettinger <python@rcn.com> parents: 73943 diff changeset	514 link_prev[NEXT] = link_next
3b2856d8614b Improve the memory utilization (and speed) of functools.lru_cache(). Raymond Hettinger <python@rcn.com> parents: 73943 diff changeset	515 link_next[PREV] = link_prev
3b2856d8614b Improve the memory utilization (and speed) of functools.lru_cache(). Raymond Hettinger <python@rcn.com> parents: 73943 diff changeset	516 last = root[PREV]
3b2856d8614b Improve the memory utilization (and speed) of functools.lru_cache(). Raymond Hettinger <python@rcn.com> parents: 73943 diff changeset	517 last[NEXT] = root[PREV] = link
3b2856d8614b Improve the memory utilization (and speed) of functools.lru_cache(). Raymond Hettinger <python@rcn.com> parents: 73943 diff changeset	518 link[PREV] = last
3b2856d8614b Improve the memory utilization (and speed) of functools.lru_cache(). Raymond Hettinger <python@rcn.com> parents: 73943 diff changeset	519 link[NEXT] = root
66582 00c8cdf53936 Issue 10593: Adopt Nick's suggestion for an lru_cache with maxsize=None. Raymond Hettinger <python@rcn.com> parents: 66578 diff changeset	520 hits += 1
72943 8365f82f8a13 Issue 13177: Make tracebacks more readable by avoiding chained exceptions in the lru_cache. Raymond Hettinger <python@rcn.com> parents: 69862 diff changeset	521 return result
8365f82f8a13 Issue 13177: Make tracebacks more readable by avoiding chained exceptions in the lru_cache. Raymond Hettinger <python@rcn.com> parents: 69862 diff changeset	522 result = user_function(args, *kwds)
8365f82f8a13 Issue 13177: Make tracebacks more readable by avoiding chained exceptions in the lru_cache. Raymond Hettinger <python@rcn.com> parents: 69862 diff changeset	523 with lock:
76675 b3aeaef6c315 Handle a possible race condition Raymond Hettinger <python@rcn.com> parents: 76656 diff changeset	524 if key in cache:
82558 1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	525 # Getting here means that this same key was added to the
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	526 # cache while the lock was released. Since the link
76675 b3aeaef6c315 Handle a possible race condition Raymond Hettinger <python@rcn.com> parents: 76656 diff changeset	527 # update is already done, we need only return the
b3aeaef6c315 Handle a possible race condition Raymond Hettinger <python@rcn.com> parents: 76656 diff changeset	528 # computed result and update the count of misses.
b3aeaef6c315 Handle a possible race condition Raymond Hettinger <python@rcn.com> parents: 76656 diff changeset	529 pass
76680 f5bb290c751a Use a flag to indicate when the circular queue is fully populated and stable. Raymond Hettinger <python@rcn.com> parents: 76675 diff changeset	530 elif full:
82558 1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	531 # Use the old root to store the new key and result.
82468 4b06fd08b78c Fix other re-entrancy nits for the lru_cache. Raymond Hettinger <python@rcn.com> parents: 82450 diff changeset	532 oldroot = root
4b06fd08b78c Fix other re-entrancy nits for the lru_cache. Raymond Hettinger <python@rcn.com> parents: 82450 diff changeset	533 oldroot[KEY] = key
4b06fd08b78c Fix other re-entrancy nits for the lru_cache. Raymond Hettinger <python@rcn.com> parents: 82450 diff changeset	534 oldroot[RESULT] = result
82558 1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	535 # Empty the oldest link and make it the new root.
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	536 # Keep a reference to the old key and old result to
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	537 # prevent their ref counts from going to zero during the
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	538 # update. That will prevent potentially arbitrary object
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	539 # clean-up code (i.e. __del__) from running while we're
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	540 # still adjusting the links.
82468 4b06fd08b78c Fix other re-entrancy nits for the lru_cache. Raymond Hettinger <python@rcn.com> parents: 82450 diff changeset	541 root = oldroot[NEXT]
4b06fd08b78c Fix other re-entrancy nits for the lru_cache. Raymond Hettinger <python@rcn.com> parents: 82450 diff changeset	542 oldkey = root[KEY]
82558 1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	543 oldresult = root[RESULT]
76004 1c22c1109824 Fix-up a comment Raymond Hettinger <python@rcn.com> parents: 76003 diff changeset	544 root[KEY] = root[RESULT] = None
82558 1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	545 # Now update the cache dictionary.
82468 4b06fd08b78c Fix other re-entrancy nits for the lru_cache. Raymond Hettinger <python@rcn.com> parents: 82450 diff changeset	546 del cache[oldkey]
82558 1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	547 # Save the potentially reentrant cache[key] assignment
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	548 # for last, after the root and links have been put in
1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	549 # a consistent state.
82468 4b06fd08b78c Fix other re-entrancy nits for the lru_cache. Raymond Hettinger <python@rcn.com> parents: 82450 diff changeset	550 cache[key] = oldroot
76680 f5bb290c751a Use a flag to indicate when the circular queue is fully populated and stable. Raymond Hettinger <python@rcn.com> parents: 76675 diff changeset	551 else:
82558 1af9f7df3a96 Improve comments and variable names. Raymond Hettinger <python@rcn.com> parents: 82470 diff changeset	552 # Put result in a new link at the front of the queue.
76680 f5bb290c751a Use a flag to indicate when the circular queue is fully populated and stable. Raymond Hettinger <python@rcn.com> parents: 76675 diff changeset	553 last = root[PREV]
f5bb290c751a Use a flag to indicate when the circular queue is fully populated and stable. Raymond Hettinger <python@rcn.com> parents: 76675 diff changeset	554 link = [last, root, key, result]
82468 4b06fd08b78c Fix other re-entrancy nits for the lru_cache. Raymond Hettinger <python@rcn.com> parents: 82450 diff changeset	555 last[NEXT] = root[PREV] = cache[key] = link
82560 a9fa8a18d18d Sync-up with 3.4 to make maintenance easier. Raymond Hettinger <python@rcn.com> parents: 82558 diff changeset	556 full = (len(cache) >= maxsize)
72943 8365f82f8a13 Issue 13177: Make tracebacks more readable by avoiding chained exceptions in the lru_cache. Raymond Hettinger <python@rcn.com> parents: 69862 diff changeset	557 misses += 1
66582 00c8cdf53936 Issue 10593: Adopt Nick's suggestion for an lru_cache with maxsize=None. Raymond Hettinger <python@rcn.com> parents: 66578 diff changeset	558 return result
63370 c55876a6fa3c Re-commit r83327 now that the release is done. Georg Brandl <georg@python.org> parents: 63357 diff changeset	559
66550 312b2916cfd4 Issue 10586: change the new functools.lru_cache implementation to expose the maximum and current cache sizes through the public statistics API. This API is now a single function that returns a named tuple. Nick Coghlan <ncoghlan@gmail.com> parents: 66441 diff changeset	560 def cache_info():
66552 f16bf4cae5d7 Neaten-up a bit. Raymond Hettinger <python@rcn.com> parents: 66550 diff changeset	561 """Report cache statistics"""
66550 312b2916cfd4 Issue 10586: change the new functools.lru_cache implementation to expose the maximum and current cache sizes through the public statistics API. This API is now a single function that returns a named tuple. Nick Coghlan <ncoghlan@gmail.com> parents: 66441 diff changeset	562 with lock:
82560 a9fa8a18d18d Sync-up with 3.4 to make maintenance easier. Raymond Hettinger <python@rcn.com> parents: 82558 diff changeset	563 return _CacheInfo(hits, misses, maxsize, len(cache))
66550 312b2916cfd4 Issue 10586: change the new functools.lru_cache implementation to expose the maximum and current cache sizes through the public statistics API. This API is now a single function that returns a named tuple. Nick Coghlan <ncoghlan@gmail.com> parents: 66441 diff changeset	564
64448 61c44793238d Adopt more descriptive attribute names as suggested on python-dev. Raymond Hettinger <python@rcn.com> parents: 64382 diff changeset	565 def cache_clear():
63823 1086dad50c74 use same quoting as the rest of the file Benjamin Peterson <benjamin@python.org> parents: 63745 diff changeset	566 """Clear the cache and cache statistics"""
82560 a9fa8a18d18d Sync-up with 3.4 to make maintenance easier. Raymond Hettinger <python@rcn.com> parents: 82558 diff changeset	567 nonlocal hits, misses, full
64016 d8d0abe61e83 Add locks to make the caches well behaved in multi-threaded code. Raymond Hettinger <python@rcn.com> parents: 63823 diff changeset	568 with lock:
d8d0abe61e83 Add locks to make the caches well behaved in multi-threaded code. Raymond Hettinger <python@rcn.com> parents: 63823 diff changeset	569 cache.clear()
75752 087da2a353e6 clear the root with the cache Benjamin Peterson <benjamin@python.org> parents: 75749 diff changeset	570 root[:] = [root, root, None, None]
82560 a9fa8a18d18d Sync-up with 3.4 to make maintenance easier. Raymond Hettinger <python@rcn.com> parents: 82558 diff changeset	571 hits = misses = 0
76680 f5bb290c751a Use a flag to indicate when the circular queue is fully populated and stable. Raymond Hettinger <python@rcn.com> parents: 76675 diff changeset	572 full = False
63370 c55876a6fa3c Re-commit r83327 now that the release is done. Georg Brandl <georg@python.org> parents: 63357 diff changeset	573
66550 312b2916cfd4 Issue 10586: change the new functools.lru_cache implementation to expose the maximum and current cache sizes through the public statistics API. This API is now a single function that returns a named tuple. Nick Coghlan <ncoghlan@gmail.com> parents: 66441 diff changeset	574 wrapper.cache_info = cache_info
64448 61c44793238d Adopt more descriptive attribute names as suggested on python-dev. Raymond Hettinger <python@rcn.com> parents: 64382 diff changeset	575 wrapper.cache_clear = cache_clear
75998 123cf2192c79 Minor cleanup: add whitespace, add comments, bring function attribute updates together. Raymond Hettinger <python@rcn.com> parents: 75803 diff changeset	576 return update_wrapper(wrapper, user_function)
66441 03d933948bf3 Clean-up docstring, comments, and whitespace. Raymond Hettinger <python@rcn.com> parents: 64776 diff changeset	577
63370 c55876a6fa3c Re-commit r83327 now that the release is done. Georg Brandl <georg@python.org> parents: 63357 diff changeset	578 return decorating_function
84039 dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	579
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	580
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	581 ################################################################################
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	582 ### singledispatch() - single-dispatch generic function decorator
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	583 ################################################################################
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	584
84411 a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	585 def _c3_merge(sequences):
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	586 """Merges MROs in sequences to a single MRO using the C3 algorithm.
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	587
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	588 Adapted from http://www.python.org/download/releases/2.3/mro/.
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	589
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	590 """
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	591 result = []
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	592 while True:
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	593 sequences = [s for s in sequences if s] # purge empty sequences
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	594 if not sequences:
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	595 return result
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	596 for s1 in sequences: # find merge candidates among seq heads
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	597 candidate = s1[0]
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	598 for s2 in sequences:
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	599 if candidate in s2[1:]:
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	600 candidate = None
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	601 break # reject the current head, it appears later
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	602 else:
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	603 break
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	604 if not candidate:
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	605 raise RuntimeError("Inconsistent hierarchy")
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	606 result.append(candidate)
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	607 # remove the chosen candidate
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	608 for seq in sequences:
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	609 if seq[0] == candidate:
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	610 del seq[0]
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	611
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	612 def _c3_mro(cls, abcs=None):
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	613 """Computes the method resolution order using extended C3 linearization.
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	614
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	615 If no abcs are given, the algorithm works exactly like the built-in C3
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	616 linearization used for method resolution.
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	617
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	618 If given, abcs is a list of abstract base classes that should be inserted
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	619 into the resulting MRO. Unrelated ABCs are ignored and don't end up in the
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	620 result. The algorithm inserts ABCs where their functionality is introduced,
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	621 i.e. issubclass(cls, abc) returns True for the class itself but returns
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	622 False for all its direct base classes. Implicit ABCs for a given class
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	623 (either registered or inferred from the presence of a special method like
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	624 __len__) are inserted directly after the last ABC explicitly listed in the
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	625 MRO of said class. If two implicit ABCs end up next to each other in the
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	626 resulting MRO, their ordering depends on the order of types in abcs.
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	627
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	628 """
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	629 for i, base in enumerate(reversed(cls.__bases__)):
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	630 if hasattr(base, '__abstractmethods__'):
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	631 boundary = len(cls.__bases__) - i
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	632 break # Bases up to the last explicit ABC are considered first.
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	633 else:
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	634 boundary = 0
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	635 abcs = list(abcs) if abcs else []
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	636 explicit_bases = list(cls.__bases__[:boundary])
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	637 abstract_bases = []
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	638 other_bases = list(cls.__bases__[boundary:])
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	639 for base in abcs:
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	640 if issubclass(cls, base) and not any(
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	641 issubclass(b, base) for b in cls.__bases__
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	642 ):
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	643 # If cls is the class that introduces behaviour described by
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	644 # an ABC base, insert said ABC to its MRO.
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	645 abstract_bases.append(base)
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	646 for base in abstract_bases:
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	647 abcs.remove(base)
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	648 explicit_c3_mros = [_c3_mro(base, abcs=abcs) for base in explicit_bases]
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	649 abstract_c3_mros = [_c3_mro(base, abcs=abcs) for base in abstract_bases]
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	650 other_c3_mros = [_c3_mro(base, abcs=abcs) for base in other_bases]
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	651 return _c3_merge(
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	652 [[cls]] +
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	653 explicit_c3_mros + abstract_c3_mros + other_c3_mros +
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	654 [explicit_bases] + [abstract_bases] + [other_bases]
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	655 )
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	656
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	657 def _compose_mro(cls, types):
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	658 """Calculates the method resolution order for a given class cls.
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	659
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	660 Includes relevant abstract base classes (with their respective bases) from
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	661 the types iterable. Uses a modified C3 linearization algorithm.
84039 dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	662
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	663 """
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	664 bases = set(cls.__mro__)
84411 a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	665 # Remove entries which are already present in the __mro__ or unrelated.
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	666 def is_related(typ):
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	667 return (typ not in bases and hasattr(typ, '__mro__')
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	668 and issubclass(cls, typ))
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	669 types = [n for n in types if is_related(n)]
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	670 # Remove entries which are strict bases of other entries (they will end up
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	671 # in the MRO anyway.
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	672 def is_strict_base(typ):
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	673 for other in types:
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	674 if typ != other and typ in other.__mro__:
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	675 return True
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	676 return False
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	677 types = [n for n in types if not is_strict_base(n)]
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	678 # Subclasses of the ABCs in types which are also implemented by
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	679 # cls can be used to stabilize ABC ordering.
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	680 type_set = set(types)
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	681 mro = []
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	682 for typ in types:
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	683 found = []
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	684 for sub in typ.__subclasses__():
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	685 if sub not in bases and issubclass(cls, sub):
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	686 found.append([s for s in sub.__mro__ if s in type_set])
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	687 if not found:
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	688 mro.append(typ)
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	689 continue
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	690 # Favor subclasses with the biggest number of useful bases
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	691 found.sort(key=len, reverse=True)
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	692 for sub in found:
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	693 for subcls in sub:
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	694 if subcls not in mro:
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	695 mro.append(subcls)
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	696 return _c3_mro(cls, abcs=mro)
84039 dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	697
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	698 def _find_impl(cls, registry):
84411 a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	699 """Returns the best matching implementation from registry for type cls.
84039 dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	700
84411 a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	701 Where there is no registered implementation for a specific type, its method
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	702 resolution order is used to find a more generic implementation.
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	703
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	704 Note: if registry does not contain an implementation for the base
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	705 object type, this function may return None.
84039 dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	706
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	707 """
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	708 mro = _compose_mro(cls, registry.keys())
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	709 match = None
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	710 for t in mro:
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	711 if match is not None:
84411 a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	712 # If match is an implicit ABC but there is another unrelated,
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	713 # equally matching implicit ABC, refuse the temptation to guess.
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	714 if (t in registry and t not in cls.__mro__
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	715 and match not in cls.__mro__
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	716 and not issubclass(match, t)):
84039 dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	717 raise RuntimeError("Ambiguous dispatch: {} or {}".format(
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	718 match, t))
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	719 break
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	720 if t in registry:
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	721 match = t
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	722 return registry.get(match)
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	723
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	724 def singledispatch(func):
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	725 """Single-dispatch generic function decorator.
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	726
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	727 Transforms a function into a generic function, which can have different
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	728 behaviours depending upon the type of its first argument. The decorated
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	729 function acts as the default implementation, and additional
84411 a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	730 implementations can be registered using the register() attribute of the
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	731 generic function.
84039 dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	732
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	733 """
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	734 registry = {}
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	735 dispatch_cache = WeakKeyDictionary()
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	736 cache_token = None
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	737
84411 a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	738 def dispatch(cls):
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	739 """generic_func.dispatch(cls) -> <function implementation>
84039 dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	740
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	741 Runs the dispatch algorithm to return the best available implementation
84411 a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	742 for the given cls registered on generic_func.
84039 dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	743
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	744 """
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	745 nonlocal cache_token
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	746 if cache_token is not None:
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	747 current_token = get_cache_token()
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	748 if cache_token != current_token:
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	749 dispatch_cache.clear()
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	750 cache_token = current_token
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	751 try:
84411 a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	752 impl = dispatch_cache[cls]
84039 dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	753 except KeyError:
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	754 try:
84411 a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	755 impl = registry[cls]
84039 dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	756 except KeyError:
84411 a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	757 impl = _find_impl(cls, registry)
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	758 dispatch_cache[cls] = impl
84039 dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	759 return impl
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	760
84411 a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	761 def register(cls, func=None):
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	762 """generic_func.register(cls, func) -> func
84039 dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	763
84411 a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	764 Registers a new implementation for the given cls on a generic_func.
84039 dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	765
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	766 """
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	767 nonlocal cache_token
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	768 if func is None:
84411 a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	769 return lambda f: register(cls, f)
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	770 registry[cls] = func
a2672dc7c805 Issue #18244: Adopt C3-based linearization in functools.singledispatch for improved ABC support Łukasz Langa <lukasz@langa.pl> parents: 84114 diff changeset	771 if cache_token is None and hasattr(cls, '__abstractmethods__'):
84039 dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	772 cache_token = get_cache_token()
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	773 dispatch_cache.clear()
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	774 return func
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	775
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	776 def wrapper(args, *kw):
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	777 return dispatch(args[0].__class__)(args, *kw)
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	778
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	779 registry[object] = func
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	780 wrapper.register = register
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	781 wrapper.dispatch = dispatch
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	782 wrapper.registry = MappingProxyType(registry)
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	783 wrapper._clear_cache = dispatch_cache.clear
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	784 update_wrapper(wrapper, func)
dfcb64f51f7b Add reference implementation for PEP 443 Łukasz Langa <lukasz@langa.pl> parents: 82561 diff changeset	785 return wrapper

Mercurial > cpython-lru_cache-weakref

annotate Lib/functools.py @ 87690:66c1c9f32567 default tip