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

annotate Lib/ast.py @ 80661:94de77bd0b4b 2.7

Issue #16194: document imp.load_dynamic problems when read several extension modules from the same binary object file.

author	Andrew Svetlov <andrew.svetlov@gmail.com>
date	Thu, 29 Nov 2012 19:51:28 +0200
parents	93a41df8c737
children

rev	line source
47541 ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	1 # -- coding: utf-8 --
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	2 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	3 ast
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	4 ~~~
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	5
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	6 The `ast` module helps Python applications to process trees of the Python
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	7 abstract syntax grammar. The abstract syntax itself might change with
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	8 each Python release; this module helps to find out programmatically what
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	9 the current grammar looks like and allows modifications of it.
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	10
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	11 An abstract syntax tree can be generated by passing `ast.PyCF_ONLY_AST` as
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	12 a flag to the `compile()` builtin function or by using the `parse()`
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	13 function from this module. The result will be a tree of objects whose
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	14 classes all inherit from `ast.AST`.
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	15
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	16 A modified abstract syntax tree can be compiled into a Python code object
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	17 using the built-in `compile()` function.
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	18
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	19 Additionally various helper functions are provided that make working with
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	20 the trees simpler. The main intention of the helper functions and this
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	21 module in general is to provide an easy to use interface for libraries
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	22 that work tightly with the python syntax (template engines for example).
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	23
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	24
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	25 :copyright: Copyright 2008 by Armin Ronacher.
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	26 :license: Python License.
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	27 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	28 from _ast import *
49559 415137d0e20a Merged revisions 66984 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 47794 diff changeset	29 from _ast import __version__
47541 ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	30
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	31
67750 93a41df8c737 Issue #11000 ast.parse doc fix (r88172) Terry Reedy <tjreedy@udel.edu> parents: 67482 diff changeset	32 def parse(source, filename='<unknown>', mode='exec'):
47541 ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	33 """
67750 93a41df8c737 Issue #11000 ast.parse doc fix (r88172) Terry Reedy <tjreedy@udel.edu> parents: 67482 diff changeset	34 Parse the source into an AST node.
93a41df8c737 Issue #11000 ast.parse doc fix (r88172) Terry Reedy <tjreedy@udel.edu> parents: 67482 diff changeset	35 Equivalent to compile(source, filename, mode, PyCF_ONLY_AST).
47541 ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	36 """
67750 93a41df8c737 Issue #11000 ast.parse doc fix (r88172) Terry Reedy <tjreedy@udel.edu> parents: 67482 diff changeset	37 return compile(source, filename, mode, PyCF_ONLY_AST)
47541 ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	38
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	39
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	40 def literal_eval(node_or_string):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	41 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	42 Safely evaluate an expression node or a string containing a Python
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	43 expression. The string or node provided may only consist of the following
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	44 Python literal structures: strings, numbers, tuples, lists, dicts, booleans,
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	45 and None.
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	46 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	47 _safe_names = {'None': None, 'True': True, 'False': False}
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	48 if isinstance(node_or_string, basestring):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	49 node_or_string = parse(node_or_string, mode='eval')
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	50 if isinstance(node_or_string, Expression):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	51 node_or_string = node_or_string.body
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	52 def _convert(node):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	53 if isinstance(node, Str):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	54 return node.s
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	55 elif isinstance(node, Num):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	56 return node.n
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	57 elif isinstance(node, Tuple):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	58 return tuple(map(_convert, node.elts))
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	59 elif isinstance(node, List):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	60 return list(map(_convert, node.elts))
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	61 elif isinstance(node, Dict):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	62 return dict((_convert(k), _convert(v)) for k, v
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	63 in zip(node.keys, node.values))
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	64 elif isinstance(node, Name):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	65 if node.id in _safe_names:
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	66 return _safe_names[node.id]
50765 c776b6d814c2 ast.literal_eval can properly evaluate complex numbers now. This fixes issue4907. Armin Ronacher <armin.ronacher@active-4.com> parents: 49559 diff changeset	67 elif isinstance(node, BinOp) and \
c776b6d814c2 ast.literal_eval can properly evaluate complex numbers now. This fixes issue4907. Armin Ronacher <armin.ronacher@active-4.com> parents: 49559 diff changeset	68 isinstance(node.op, (Add, Sub)) and \
c776b6d814c2 ast.literal_eval can properly evaluate complex numbers now. This fixes issue4907. Armin Ronacher <armin.ronacher@active-4.com> parents: 49559 diff changeset	69 isinstance(node.right, Num) and \
c776b6d814c2 ast.literal_eval can properly evaluate complex numbers now. This fixes issue4907. Armin Ronacher <armin.ronacher@active-4.com> parents: 49559 diff changeset	70 isinstance(node.right.n, complex) and \
c776b6d814c2 ast.literal_eval can properly evaluate complex numbers now. This fixes issue4907. Armin Ronacher <armin.ronacher@active-4.com> parents: 49559 diff changeset	71 isinstance(node.left, Num) and \
c776b6d814c2 ast.literal_eval can properly evaluate complex numbers now. This fixes issue4907. Armin Ronacher <armin.ronacher@active-4.com> parents: 49559 diff changeset	72 isinstance(node.left.n, (int, long, float)):
c776b6d814c2 ast.literal_eval can properly evaluate complex numbers now. This fixes issue4907. Armin Ronacher <armin.ronacher@active-4.com> parents: 49559 diff changeset	73 left = node.left.n
c776b6d814c2 ast.literal_eval can properly evaluate complex numbers now. This fixes issue4907. Armin Ronacher <armin.ronacher@active-4.com> parents: 49559 diff changeset	74 right = node.right.n
c776b6d814c2 ast.literal_eval can properly evaluate complex numbers now. This fixes issue4907. Armin Ronacher <armin.ronacher@active-4.com> parents: 49559 diff changeset	75 if isinstance(node.op, Add):
c776b6d814c2 ast.literal_eval can properly evaluate complex numbers now. This fixes issue4907. Armin Ronacher <armin.ronacher@active-4.com> parents: 49559 diff changeset	76 return left + right
c776b6d814c2 ast.literal_eval can properly evaluate complex numbers now. This fixes issue4907. Armin Ronacher <armin.ronacher@active-4.com> parents: 49559 diff changeset	77 else:
c776b6d814c2 ast.literal_eval can properly evaluate complex numbers now. This fixes issue4907. Armin Ronacher <armin.ronacher@active-4.com> parents: 49559 diff changeset	78 return left - right
47541 ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	79 raise ValueError('malformed string')
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	80 return _convert(node_or_string)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	81
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	82
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	83 def dump(node, annotate_fields=True, include_attributes=False):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	84 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	85 Return a formatted dump of the tree in node. This is mainly useful for
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	86 debugging purposes. The returned string will show the names and the values
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	87 for fields. This makes the code impossible to evaluate, so if evaluation is
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	88 wanted annotate_fields must be set to False. Attributes such as line
47794 16b7c500b753 Docstring correction Andrew M. Kuchling <amk@amk.ca> parents: 47541 diff changeset	89 numbers and column offsets are not dumped by default. If this is wanted,
47541 ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	90 include_attributes can be set to True.
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	91 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	92 def _format(node):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	93 if isinstance(node, AST):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	94 fields = [(a, _format(b)) for a, b in iter_fields(node)]
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	95 rv = '%s(%s' % (node.__class__.__name__, ', '.join(
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	96 ('%s=%s' % field for field in fields)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	97 if annotate_fields else
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	98 (b for a, b in fields)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	99 ))
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	100 if include_attributes and node._attributes:
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	101 rv += fields and ', ' or ' '
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	102 rv += ', '.join('%s=%s' % (a, _format(getattr(node, a)))
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	103 for a in node._attributes)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	104 return rv + ')'
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	105 elif isinstance(node, list):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	106 return '[%s]' % ', '.join(_format(x) for x in node)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	107 return repr(node)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	108 if not isinstance(node, AST):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	109 raise TypeError('expected AST, got %r' % node.__class__.__name__)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	110 return _format(node)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	111
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	112
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	113 def copy_location(new_node, old_node):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	114 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	115 Copy source location (`lineno` and `col_offset` attributes) from
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	116 old_node to new_node if possible, and return new_node.
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	117 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	118 for attr in 'lineno', 'col_offset':
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	119 if attr in old_node._attributes and attr in new_node._attributes \
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	120 and hasattr(old_node, attr):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	121 setattr(new_node, attr, getattr(old_node, attr))
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	122 return new_node
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	123
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	124
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	125 def fix_missing_locations(node):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	126 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	127 When you compile a node tree with compile(), the compiler expects lineno and
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	128 col_offset attributes for every node that supports them. This is rather
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	129 tedious to fill in for generated nodes, so this helper adds these attributes
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	130 recursively where not already set, by setting them to the values of the
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	131 parent node. It works recursively starting at node.
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	132 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	133 def _fix(node, lineno, col_offset):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	134 if 'lineno' in node._attributes:
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	135 if not hasattr(node, 'lineno'):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	136 node.lineno = lineno
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	137 else:
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	138 lineno = node.lineno
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	139 if 'col_offset' in node._attributes:
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	140 if not hasattr(node, 'col_offset'):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	141 node.col_offset = col_offset
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	142 else:
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	143 col_offset = node.col_offset
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	144 for child in iter_child_nodes(node):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	145 _fix(child, lineno, col_offset)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	146 _fix(node, 1, 0)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	147 return node
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	148
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	149
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	150 def increment_lineno(node, n=1):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	151 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	152 Increment the line number of each node in the tree starting at node by n.
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	153 This is useful to "move code" to a different location in a file.
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	154 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	155 for child in walk(node):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	156 if 'lineno' in child._attributes:
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	157 child.lineno = getattr(child, 'lineno', 0) + n
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	158 return node
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	159
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	160
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	161 def iter_fields(node):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	162 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	163 Yield a tuple of ``(fieldname, value)`` for each field in ``node._fields``
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	164 that is present on node.
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	165 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	166 for field in node._fields:
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	167 try:
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	168 yield field, getattr(node, field)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	169 except AttributeError:
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	170 pass
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	171
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	172
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	173 def iter_child_nodes(node):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	174 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	175 Yield all direct child nodes of node, that is, all fields that are nodes
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	176 and all items of fields that are lists of nodes.
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	177 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	178 for name, field in iter_fields(node):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	179 if isinstance(field, AST):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	180 yield field
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	181 elif isinstance(field, list):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	182 for item in field:
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	183 if isinstance(item, AST):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	184 yield item
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	185
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	186
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	187 def get_docstring(node, clean=True):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	188 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	189 Return the docstring for the given node or None if no docstring can
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	190 be found. If the node provided does not have docstrings a TypeError
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	191 will be raised.
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	192 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	193 if not isinstance(node, (FunctionDef, ClassDef, Module)):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	194 raise TypeError("%r can't have docstrings" % node.__class__.__name__)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	195 if node.body and isinstance(node.body[0], Expr) and \
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	196 isinstance(node.body[0].value, Str):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	197 if clean:
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	198 import inspect
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	199 return inspect.cleandoc(node.body[0].value.s)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	200 return node.body[0].value.s
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	201
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	202
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	203 def walk(node):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	204 """
67482 7ec21653a4d1 Merged revisions 87876-87877 via svnmerge from Georg Brandl <georg@python.org> parents: 50765 diff changeset	205 Recursively yield all descendant nodes in the tree starting at node
7ec21653a4d1 Merged revisions 87876-87877 via svnmerge from Georg Brandl <georg@python.org> parents: 50765 diff changeset	206 (including node itself), in no specified order. This is useful if you
7ec21653a4d1 Merged revisions 87876-87877 via svnmerge from Georg Brandl <georg@python.org> parents: 50765 diff changeset	207 only want to modify nodes in place and don't care about the context.
47541 ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	208 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	209 from collections import deque
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	210 todo = deque([node])
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	211 while todo:
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	212 node = todo.popleft()
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	213 todo.extend(iter_child_nodes(node))
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	214 yield node
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	215
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	216
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	217 class NodeVisitor(object):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	218 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	219 A node visitor base class that walks the abstract syntax tree and calls a
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	220 visitor function for every node found. This function may return a value
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	221 which is forwarded by the `visit` method.
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	222
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	223 This class is meant to be subclassed, with the subclass adding visitor
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	224 methods.
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	225
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	226 Per default the visitor functions for the nodes are ``'visit_'`` +
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	227 class name of the node. So a `TryFinally` node visit function would
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	228 be `visit_TryFinally`. This behavior can be changed by overriding
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	229 the `visit` method. If no visitor function exists for a node
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	230 (return value `None`) the `generic_visit` visitor is used instead.
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	231
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	232 Don't use the `NodeVisitor` if you want to apply changes to nodes during
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	233 traversing. For this a special visitor exists (`NodeTransformer`) that
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	234 allows modifications.
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	235 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	236
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	237 def visit(self, node):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	238 """Visit a node."""
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	239 method = 'visit_' + node.__class__.__name__
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	240 visitor = getattr(self, method, self.generic_visit)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	241 return visitor(node)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	242
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	243 def generic_visit(self, node):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	244 """Called if no explicit visitor function exists for a node."""
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	245 for field, value in iter_fields(node):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	246 if isinstance(value, list):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	247 for item in value:
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	248 if isinstance(item, AST):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	249 self.visit(item)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	250 elif isinstance(value, AST):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	251 self.visit(value)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	252
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	253
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	254 class NodeTransformer(NodeVisitor):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	255 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	256 A :class:`NodeVisitor` subclass that walks the abstract syntax tree and
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	257 allows modification of nodes.
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	258
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	259 The `NodeTransformer` will walk the AST and use the return value of the
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	260 visitor methods to replace or remove the old node. If the return value of
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	261 the visitor method is ``None``, the node will be removed from its location,
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	262 otherwise it is replaced with the return value. The return value may be the
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	263 original node in which case no replacement takes place.
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	264
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	265 Here is an example transformer that rewrites all occurrences of name lookups
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	266 (``foo``) to ``data['foo']``::
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	267
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	268 class RewriteName(NodeTransformer):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	269
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	270 def visit_Name(self, node):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	271 return copy_location(Subscript(
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	272 value=Name(id='data', ctx=Load()),
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	273 slice=Index(value=Str(s=node.id)),
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	274 ctx=node.ctx
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	275 ), node)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	276
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	277 Keep in mind that if the node you're operating on has child nodes you must
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	278 either transform the child nodes yourself or call the :meth:`generic_visit`
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	279 method for the node first.
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	280
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	281 For nodes that were part of a collection of statements (that applies to all
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	282 statement nodes), the visitor may also return a list of nodes rather than
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	283 just a single node.
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	284
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	285 Usually you use the transformer like this::
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	286
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	287 node = YourTransformer().visit(node)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	288 """
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	289
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	290 def generic_visit(self, node):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	291 for field, old_value in iter_fields(node):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	292 old_value = getattr(node, field, None)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	293 if isinstance(old_value, list):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	294 new_values = []
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	295 for value in old_value:
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	296 if isinstance(value, AST):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	297 value = self.visit(value)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	298 if value is None:
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	299 continue
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	300 elif not isinstance(value, AST):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	301 new_values.extend(value)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	302 continue
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	303 new_values.append(value)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	304 old_value[:] = new_values
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	305 elif isinstance(old_value, AST):
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	306 new_node = self.visit(old_value)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	307 if new_node is None:
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	308 delattr(node, field)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	309 else:
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	310 setattr(node, field, new_node)
ed572d260fa7 Add the "ast" module, containing helpers to ease use of the "_ast" classes. Georg Brandl <georg@python.org> parents: diff changeset	311 return node

Mercurial > cpython-lru_cache-weakref

annotate Lib/ast.py @ 80661:94de77bd0b4b 2.7