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

annotate Lib/random.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	0b6052f2a8ee
children

rev	line source
11707 6f4146846337 The third and final doc-string sweep by Ka-Ping Yee. Guido van Rossum <guido@python.org> parents: 11200 diff changeset	1 """Random variable generators.
6f4146846337 The third and final doc-string sweep by Ka-Ping Yee. Guido van Rossum <guido@python.org> parents: 11200 diff changeset	2
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	3 integers
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	4 --------
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	5 uniform within range
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	6
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	7 sequences
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	8 ---------
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	9 pick random element
26155 8ceb455f5541 SF patch 629637: Add sample(population, k) method to the random module. Raymond Hettinger <python@rcn.com> parents: 24861 diff changeset	10 pick random sample
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	11 generate random permutation
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	12
11707 6f4146846337 The third and final doc-string sweep by Ka-Ping Yee. Guido van Rossum <guido@python.org> parents: 11200 diff changeset	13 distributions on the real line:
6f4146846337 The third and final doc-string sweep by Ka-Ping Yee. Guido van Rossum <guido@python.org> parents: 11200 diff changeset	14 ------------------------------
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	15 uniform
46034 0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	16 triangular
11707 6f4146846337 The third and final doc-string sweep by Ka-Ping Yee. Guido van Rossum <guido@python.org> parents: 11200 diff changeset	17 normal (Gaussian)
6f4146846337 The third and final doc-string sweep by Ka-Ping Yee. Guido van Rossum <guido@python.org> parents: 11200 diff changeset	18 lognormal
6f4146846337 The third and final doc-string sweep by Ka-Ping Yee. Guido van Rossum <guido@python.org> parents: 11200 diff changeset	19 negative exponential
6f4146846337 The third and final doc-string sweep by Ka-Ping Yee. Guido van Rossum <guido@python.org> parents: 11200 diff changeset	20 gamma
6f4146846337 The third and final doc-string sweep by Ka-Ping Yee. Guido van Rossum <guido@python.org> parents: 11200 diff changeset	21 beta
26829 f64c96922708 SF patch 658251: Install a C implementation of the Mersenne Twister as the Raymond Hettinger <python@rcn.com> parents: 26564 diff changeset	22 pareto
f64c96922708 SF patch 658251: Install a C implementation of the Mersenne Twister as the Raymond Hettinger <python@rcn.com> parents: 26564 diff changeset	23 Weibull
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	24
11707 6f4146846337 The third and final doc-string sweep by Ka-Ping Yee. Guido van Rossum <guido@python.org> parents: 11200 diff changeset	25 distributions on the circle (angles 0 to 2pi)
6f4146846337 The third and final doc-string sweep by Ka-Ping Yee. Guido van Rossum <guido@python.org> parents: 11200 diff changeset	26 ---------------------------------------------
6f4146846337 The third and final doc-string sweep by Ka-Ping Yee. Guido van Rossum <guido@python.org> parents: 11200 diff changeset	27 circular uniform
6f4146846337 The third and final doc-string sweep by Ka-Ping Yee. Guido van Rossum <guido@python.org> parents: 11200 diff changeset	28 von Mises
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	29
26829 f64c96922708 SF patch 658251: Install a C implementation of the Mersenne Twister as the Raymond Hettinger <python@rcn.com> parents: 26564 diff changeset	30 General notes on the underlying Mersenne Twister core generator:
16272 835e9dd54bfb The combo of getstate/setstate/jumpahead is very powerful, but needs Tim Peters <tim.peters@gmail.com> parents: 16271 diff changeset	31
26829 f64c96922708 SF patch 658251: Install a C implementation of the Mersenne Twister as the Raymond Hettinger <python@rcn.com> parents: 26564 diff changeset	32 * The period is 2**19937-1.
39442 654c380cf8b9 Merged revisions 46753-51188 via svnmerge from Thomas Wouters <thomas@python.org> parents: 37879 diff changeset	33 * It is one of the most extensively tested generators in existence.
654c380cf8b9 Merged revisions 46753-51188 via svnmerge from Thomas Wouters <thomas@python.org> parents: 37879 diff changeset	34 * The random() method is implemented in C, executes in a single Python step,
654c380cf8b9 Merged revisions 46753-51188 via svnmerge from Thomas Wouters <thomas@python.org> parents: 37879 diff changeset	35 and is, therefore, threadsafe.
16272 835e9dd54bfb The combo of getstate/setstate/jumpahead is very powerful, but needs Tim Peters <tim.peters@gmail.com> parents: 16271 diff changeset	36
11707 6f4146846337 The third and final doc-string sweep by Ka-Ping Yee. Guido van Rossum <guido@python.org> parents: 11200 diff changeset	37 """
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	38
30649 8841d34a2c37 SF bug #812202: randint is always even Raymond Hettinger <python@rcn.com> parents: 30346 diff changeset	39 from warnings import warn as _warn
8841d34a2c37 SF bug #812202: randint is always even Raymond Hettinger <python@rcn.com> parents: 30346 diff changeset	40 from types import MethodType as _MethodType, BuiltinMethodType as _BuiltinMethodType
35359 c5bf5685267b Implement random.sample() using sets instead of dicts. Raymond Hettinger <python@rcn.com> parents: 34942 diff changeset	41 from math import log as _log, exp as _exp, pi as _pi, e as _e, ceil as _ceil
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	42 from math import sqrt as _sqrt, acos as _acos, cos as _cos, sin as _sin
33409 8e23bd3d5b1a Fulfill Martin's request to use try/except rather than a "look before Raymond Hettinger <python@rcn.com> parents: 33399 diff changeset	43 from os import urandom as _urandom
86273 0b6052f2a8ee Issue #19218: Rename collections.abc to _collections_abc in order to speed up interpreter start Christian Heimes <christian@cheimes.de> parents: 85991 diff changeset	44 from _collections_abc import Set as _Set, Sequence as _Sequence
66786 f4f56efa2870 Update whatsnew. Salt the random number seed. Raymond Hettinger <python@rcn.com> parents: 64569 diff changeset	45 from hashlib import sha512 as _sha512
8455 af9273b1073a Make gauss() semi-thread-safe. It can still give duplicate results, Guido van Rossum <guido@python.org> parents: 8393 diff changeset	46
26155 8ceb455f5541 SF patch 629637: Add sample(population, k) method to the random module. Raymond Hettinger <python@rcn.com> parents: 24861 diff changeset	47 __all__ = ["Random","seed","random","uniform","randint","choice","sample",
16613 f68dbffff927 bunch more __all__ lists Skip Montanaro <skip@pobox.com> parents: 16386 diff changeset	48 "randrange","shuffle","normalvariate","lognormvariate",
46034 0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	49 "expovariate","vonmisesvariate","gammavariate","triangular",
30068 171814f5dcc6 Removed deprecated functions Raymond Hettinger <python@rcn.com> parents: 29586 diff changeset	50 "gauss","betavariate","paretovariate","weibullvariate",
44662 c25760c21397 Remove defunct parts of the random module Raymond Hettinger <python@rcn.com> parents: 44129 diff changeset	51 "getstate","setstate", "getrandbits",
33481 eacdc29606d8 SF #1027105: HardwareRandom should be renamed OSRandom Raymond Hettinger <python@rcn.com> parents: 33409 diff changeset	52 "SystemRandom"]
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	53
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	54 NV_MAGICCONST = 4 * _exp(-0.5)/_sqrt(2.0)
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	55 TWOPI = 2.0*_pi
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	56 LOG4 = _log(4.0)
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	57 SG_MAGICCONST = 1.0 + _log(4.5)
30649 8841d34a2c37 SF bug #812202: randint is always even Raymond Hettinger <python@rcn.com> parents: 30346 diff changeset	58 BPF = 53 # Number of bits in a float
33350 c44f083465f9 HardwareRandom: Go back to multiplying by 2*-BPF instead of using Tim Peters <tim.peters@gmail.com>* parents: 33349 diff changeset	59 RECIP_BPF = 2**-BPF
8393 7669ddf0e7d4 Add Interfaces to replace remaining needs for importing whrandom. Guido van Rossum <guido@python.org> parents: 7881 diff changeset	60
33329 97fca735c8da Teach the random module about os.urandom(). Raymond Hettinger <python@rcn.com> parents: 32287 diff changeset	61
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	62 # Translated by Guido van Rossum from C source provided by
26829 f64c96922708 SF patch 658251: Install a C implementation of the Mersenne Twister as the Raymond Hettinger <python@rcn.com> parents: 26564 diff changeset	63 # Adrian Baddeley. Adapted by Raymond Hettinger for use with
33349 ddba154c0e00 Take advantage of the math library's ldexp for assembling a float by Raymond Hettinger <python@rcn.com> parents: 33329 diff changeset	64 # the Mersenne Twister and os.urandom() core generators.
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	65
27131 e87d590a5de1 Much clearer when super() is used. Raymond Hettinger <python@rcn.com> parents: 27094 diff changeset	66 import _random
26829 f64c96922708 SF patch 658251: Install a C implementation of the Mersenne Twister as the Raymond Hettinger <python@rcn.com> parents: 26564 diff changeset	67
27131 e87d590a5de1 Much clearer when super() is used. Raymond Hettinger <python@rcn.com> parents: 27094 diff changeset	68 class Random(_random.Random):
23531 a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	69 """Random number generator base class used by bound module functions.
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	70
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	71 Used to instantiate instances of Random to get generators that don't
44662 c25760c21397 Remove defunct parts of the random module Raymond Hettinger <python@rcn.com> parents: 44129 diff changeset	72 share state.
23531 a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	73
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	74 Class Random can also be subclassed if you want to use a different basic
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	75 generator of your own devising: in that case, override the following
44662 c25760c21397 Remove defunct parts of the random module Raymond Hettinger <python@rcn.com> parents: 44129 diff changeset	76 methods: random(), seed(), getstate(), and setstate().
48596 13b2e11f3cf5 Merged revisions 65259,65263,65296,65307,65321 via svnmerge from Benjamin Peterson <benjamin@python.org> parents: 46034 diff changeset	77 Optionally, implement a getrandbits() method so that randrange()
30649 8841d34a2c37 SF bug #812202: randint is always even Raymond Hettinger <python@rcn.com> parents: 30346 diff changeset	78 can cover arbitrarily large ranges.
23536 0a4c92559a0b Whitespace normalized. Raymond Hettinger <python@rcn.com> parents: 23531 diff changeset	79
23531 a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	80 """
8393 7669ddf0e7d4 Add Interfaces to replace remaining needs for importing whrandom. Guido van Rossum <guido@python.org> parents: 7881 diff changeset	81
44129 b637349336fd Merged revisions 59275-59303 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 43020 diff changeset	82 VERSION = 3 # used by getstate/setstate
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	83
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	84 def __init__(self, x=None):
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	85 """Initialize an instance.
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	86
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	87 Optional argument x controls seeding, as for Random.seed().
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	88 """
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	89
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	90 self.seed(x)
26829 f64c96922708 SF patch 658251: Install a C implementation of the Mersenne Twister as the Raymond Hettinger <python@rcn.com> parents: 26564 diff changeset	91 self.gauss_next = None
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	92
64510 65642f085c55 Document which part of the random module module are guaranteed. Raymond Hettinger <python@rcn.com> parents: 57584 diff changeset	93 def seed(self, a=None, version=2):
16379 5f0683a69efc Change random.seed() so that it can get at the full range of possible Tim Peters <tim.peters@gmail.com> parents: 16292 diff changeset	94 """Initialize internal state from hashable object.
5f0683a69efc Change random.seed() so that it can get at the full range of possible Tim Peters <tim.peters@gmail.com> parents: 16292 diff changeset	95
33481 eacdc29606d8 SF #1027105: HardwareRandom should be renamed OSRandom Raymond Hettinger <python@rcn.com> parents: 33409 diff changeset	96 None or no argument seeds from current time or from an operating
eacdc29606d8 SF #1027105: HardwareRandom should be renamed OSRandom Raymond Hettinger <python@rcn.com> parents: 33409 diff changeset	97 system specific randomness source if available.
8393 7669ddf0e7d4 Add Interfaces to replace remaining needs for importing whrandom. Guido van Rossum <guido@python.org> parents: 7881 diff changeset	98
77303 e2739145657d Issue #14926: fix docstring highlight Sandro Tosi <sandro.tosi@gmail.com> parents: 73503 diff changeset	99 For version 2 (the default), all of the bits are used if a is a str,
64567 b1865ca7b65c * Remove dependency on binascii.hexlify by using int.from_bytes(). Raymond Hettinger <python@rcn.com> parents: 64553 diff changeset	100 bytes, or bytearray. For version 1, the hash() of a is used instead.
64510 65642f085c55 Document which part of the random module module are guaranteed. Raymond Hettinger <python@rcn.com> parents: 57584 diff changeset	101
64567 b1865ca7b65c * Remove dependency on binascii.hexlify by using int.from_bytes(). Raymond Hettinger <python@rcn.com> parents: 64553 diff changeset	102 If a is an int, all bits are used.
64510 65642f085c55 Document which part of the random module module are guaranteed. Raymond Hettinger <python@rcn.com> parents: 57584 diff changeset	103
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	104 """
8393 7669ddf0e7d4 Add Interfaces to replace remaining needs for importing whrandom. Guido van Rossum <guido@python.org> parents: 7881 diff changeset	105
30114 9f6e2dee1892 SF bug #778964: bad seed in python 2.3 random Raymond Hettinger <python@rcn.com> parents: 30068 diff changeset	106 if a is None:
33409 8e23bd3d5b1a Fulfill Martin's request to use try/except rather than a "look before Raymond Hettinger <python@rcn.com> parents: 33399 diff changeset	107 try:
64567 b1865ca7b65c * Remove dependency on binascii.hexlify by using int.from_bytes(). Raymond Hettinger <python@rcn.com> parents: 64553 diff changeset	108 a = int.from_bytes(_urandom(32), 'big')
33409 8e23bd3d5b1a Fulfill Martin's request to use try/except rather than a "look before Raymond Hettinger <python@rcn.com> parents: 33399 diff changeset	109 except NotImplementedError:
33329 97fca735c8da Teach the random module about os.urandom(). Raymond Hettinger <python@rcn.com> parents: 32287 diff changeset	110 import time
40644 1c26505c1de6 Rip out 'long' and 'L'-suffixed integer literals. Guido van Rossum <guido@python.org> parents: 40582 diff changeset	111 a = int(time.time() * 256) # use fractional seconds
33329 97fca735c8da Teach the random module about os.urandom(). Raymond Hettinger <python@rcn.com> parents: 32287 diff changeset	112
66786 f4f56efa2870 Update whatsnew. Salt the random number seed. Raymond Hettinger <python@rcn.com> parents: 64569 diff changeset	113 if version == 2:
f4f56efa2870 Update whatsnew. Salt the random number seed. Raymond Hettinger <python@rcn.com> parents: 64569 diff changeset	114 if isinstance(a, (str, bytes, bytearray)):
f4f56efa2870 Update whatsnew. Salt the random number seed. Raymond Hettinger <python@rcn.com> parents: 64569 diff changeset	115 if isinstance(a, str):
69857 1a56775c6e54 Avoid codec spelling issues by just using the utf-8 default. Raymond Hettinger <python@rcn.com> parents: 69363 diff changeset	116 a = a.encode()
66786 f4f56efa2870 Update whatsnew. Salt the random number seed. Raymond Hettinger <python@rcn.com> parents: 64569 diff changeset	117 a += _sha512(a).digest()
f4f56efa2870 Update whatsnew. Salt the random number seed. Raymond Hettinger <python@rcn.com> parents: 64569 diff changeset	118 a = int.from_bytes(a, 'big')
64510 65642f085c55 Document which part of the random module module are guaranteed. Raymond Hettinger <python@rcn.com> parents: 57584 diff changeset	119
42084 229c28cb9afb Merged revisions 55817-55961 via svnmerge from Guido van Rossum <guido@python.org> parents: 41642 diff changeset	120 super().seed(a)
23380 9be01b7b6c80 random.gauss() uses a piece of hidden state used by nothing else, Tim Peters <tim.peters@gmail.com> parents: 23023 diff changeset	121 self.gauss_next = None
9be01b7b6c80 random.gauss() uses a piece of hidden state used by nothing else, Tim Peters <tim.peters@gmail.com> parents: 23023 diff changeset	122
16265 d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	123 def getstate(self):
d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	124 """Return internal state; can be passed to setstate() later."""
42084 229c28cb9afb Merged revisions 55817-55961 via svnmerge from Guido van Rossum <guido@python.org> parents: 41642 diff changeset	125 return self.VERSION, super().getstate(), self.gauss_next
16265 d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	126
d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	127 def setstate(self, state):
d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	128 """Restore internal state from object returned by getstate()."""
d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	129 version = state[0]
44129 b637349336fd Merged revisions 59275-59303 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 43020 diff changeset	130 if version == 3:
26829 f64c96922708 SF patch 658251: Install a C implementation of the Mersenne Twister as the Raymond Hettinger <python@rcn.com> parents: 26564 diff changeset	131 version, internalstate, self.gauss_next = state
42084 229c28cb9afb Merged revisions 55817-55961 via svnmerge from Guido van Rossum <guido@python.org> parents: 41642 diff changeset	132 super().setstate(internalstate)
44129 b637349336fd Merged revisions 59275-59303 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 43020 diff changeset	133 elif version == 2:
b637349336fd Merged revisions 59275-59303 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 43020 diff changeset	134 version, internalstate, self.gauss_next = state
b637349336fd Merged revisions 59275-59303 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 43020 diff changeset	135 # In version 2, the state was saved as signed ints, which causes
b637349336fd Merged revisions 59275-59303 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 43020 diff changeset	136 # inconsistencies between 32/64-bit systems. The state is
b637349336fd Merged revisions 59275-59303 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 43020 diff changeset	137 # really unsigned 32-bit ints, so we convert negative ints from
b637349336fd Merged revisions 59275-59303 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 43020 diff changeset	138 # version 2 to positive longs for version 3.
b637349336fd Merged revisions 59275-59303 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 43020 diff changeset	139 try:
64523 6095ea9dcff4 Fix test that depends on a particular implementation of random.choice(). Raymond Hettinger <python@rcn.com> parents: 64517 diff changeset	140 internalstate = tuple(x % (2**32) for x in internalstate)
44129 b637349336fd Merged revisions 59275-59303 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 43020 diff changeset	141 except ValueError as e:
b637349336fd Merged revisions 59275-59303 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 43020 diff changeset	142 raise TypeError from e
64567 b1865ca7b65c * Remove dependency on binascii.hexlify by using int.from_bytes(). Raymond Hettinger <python@rcn.com> parents: 64553 diff changeset	143 super().setstate(internalstate)
16265 d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	144 else:
d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	145 raise ValueError("state with version %s passed to "
d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	146 "Random.setstate() of version %s" %
d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	147 (version, self.VERSION))
d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	148
d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	149 ## ---- Methods below this point do not need to be overridden when
d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	150 ## ---- subclassing for the purpose of using a different core generator.
d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	151
d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	152 ## -------------------- pickle support -------------------
d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	153
83063 68ed5b2ca867 #17489: Add explanatory comment that __getstate__ is not called. R David Murray <rdmurray@bitdance.com> parents: 82142 diff changeset	154 # Issue 17489: Since __reduce__ was defined to fix #759889 this is no
68ed5b2ca867 #17489: Add explanatory comment that __getstate__ is not called. R David Murray <rdmurray@bitdance.com> parents: 82142 diff changeset	155 # longer called; we leave it here because it has been here since random was
68ed5b2ca867 #17489: Add explanatory comment that __getstate__ is not called. R David Murray <rdmurray@bitdance.com> parents: 82142 diff changeset	156 # rewritten back in 2001 and why risk breaking something.
16265 d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	157 def __getstate__(self): # for pickle
d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	158 return self.getstate()
d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	159
d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	160 def __setstate__(self, state): # for pickle
d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	161 self.setstate(state)
d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	162
29586 8b163370372d SF bug #759889: Pickling of Random is broken Raymond Hettinger <python@rcn.com> parents: 29539 diff changeset	163 def __reduce__(self):
8b163370372d SF bug #759889: Pickling of Random is broken Raymond Hettinger <python@rcn.com> parents: 29539 diff changeset	164 return self.__class__, (), self.getstate()
8b163370372d SF bug #759889: Pickling of Random is broken Raymond Hettinger <python@rcn.com> parents: 29539 diff changeset	165
16265 d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	166 ## -------------------- integer methods -------------------
d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	167
85988 0899960835f5 Minor clean-up of function parameters in random(). Raymond Hettinger <python@rcn.com> parents: 85661 diff changeset	168 def randrange(self, start, stop=None, step=1, _int=int):
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	169 """Choose a random item from range(start, stop[, step]).
8393 7669ddf0e7d4 Add Interfaces to replace remaining needs for importing whrandom. Guido van Rossum <guido@python.org> parents: 7881 diff changeset	170
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	171 This fixes the problem with randint() which includes the
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	172 endpoint; in Python this is usually not what you want.
64511 11ba6397e3a4 Minor code cleanup Raymond Hettinger <python@rcn.com> parents: 64510 diff changeset	173
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	174 """
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	175
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	176 # This code is a bit messy to make it fast for the
24861 4e795fe9f54b SF bug 594996: OverflowError in random.randrange Tim Peters <tim.peters@gmail.com> parents: 23536 diff changeset	177 # common case while still doing adequate error checking.
85988 0899960835f5 Minor clean-up of function parameters in random(). Raymond Hettinger <python@rcn.com> parents: 85661 diff changeset	178 istart = _int(start)
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	179 if istart != start:
43020 907a45df1295 Raise statement normalization in Lib/. Collin Winter <collinw@gmail.com> parents: 42084 diff changeset	180 raise ValueError("non-integer arg 1 for randrange()")
64511 11ba6397e3a4 Minor code cleanup Raymond Hettinger <python@rcn.com> parents: 64510 diff changeset	181 if stop is None:
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	182 if istart > 0:
64512 c2f8418a0e14 Issues #7889, #9025 and #9379: Improvements to the random module. Raymond Hettinger <python@rcn.com> parents: 64511 diff changeset	183 return self._randbelow(istart)
43020 907a45df1295 Raise statement normalization in Lib/. Collin Winter <collinw@gmail.com> parents: 42084 diff changeset	184 raise ValueError("empty range for randrange()")
24861 4e795fe9f54b SF bug 594996: OverflowError in random.randrange Tim Peters <tim.peters@gmail.com> parents: 23536 diff changeset	185
4e795fe9f54b SF bug 594996: OverflowError in random.randrange Tim Peters <tim.peters@gmail.com> parents: 23536 diff changeset	186 # stop argument supplied.
85988 0899960835f5 Minor clean-up of function parameters in random(). Raymond Hettinger <python@rcn.com> parents: 85661 diff changeset	187 istop = _int(stop)
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	188 if istop != stop:
43020 907a45df1295 Raise statement normalization in Lib/. Collin Winter <collinw@gmail.com> parents: 42084 diff changeset	189 raise ValueError("non-integer stop for randrange()")
30649 8841d34a2c37 SF bug #812202: randint is always even Raymond Hettinger <python@rcn.com> parents: 30346 diff changeset	190 width = istop - istart
8841d34a2c37 SF bug #812202: randint is always even Raymond Hettinger <python@rcn.com> parents: 30346 diff changeset	191 if step == 1 and width > 0:
64516 6ba20b9039ae Small clean-ups. Raymond Hettinger <python@rcn.com> parents: 64512 diff changeset	192 return istart + self._randbelow(width)
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	193 if step == 1:
43020 907a45df1295 Raise statement normalization in Lib/. Collin Winter <collinw@gmail.com> parents: 42084 diff changeset	194 raise ValueError("empty range for randrange() (%d,%d, %d)" % (istart, istop, width))
24861 4e795fe9f54b SF bug 594996: OverflowError in random.randrange Tim Peters <tim.peters@gmail.com> parents: 23536 diff changeset	195
4e795fe9f54b SF bug 594996: OverflowError in random.randrange Tim Peters <tim.peters@gmail.com> parents: 23536 diff changeset	196 # Non-unit step argument supplied.
85988 0899960835f5 Minor clean-up of function parameters in random(). Raymond Hettinger <python@rcn.com> parents: 85661 diff changeset	197 istep = _int(step)
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	198 if istep != step:
43020 907a45df1295 Raise statement normalization in Lib/. Collin Winter <collinw@gmail.com> parents: 42084 diff changeset	199 raise ValueError("non-integer step for randrange()")
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	200 if istep > 0:
33597 355b15e4a4da Use floor division operator. Raymond Hettinger <python@rcn.com> parents: 33481 diff changeset	201 n = (width + istep - 1) // istep
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	202 elif istep < 0:
33597 355b15e4a4da Use floor division operator. Raymond Hettinger <python@rcn.com> parents: 33481 diff changeset	203 n = (width + istep + 1) // istep
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	204 else:
43020 907a45df1295 Raise statement normalization in Lib/. Collin Winter <collinw@gmail.com> parents: 42084 diff changeset	205 raise ValueError("zero step for randrange()")
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	206
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	207 if n <= 0:
43020 907a45df1295 Raise statement normalization in Lib/. Collin Winter <collinw@gmail.com> parents: 42084 diff changeset	208 raise ValueError("empty range for randrange()")
30649 8841d34a2c37 SF bug #812202: randint is always even Raymond Hettinger <python@rcn.com> parents: 30346 diff changeset	209
64512 c2f8418a0e14 Issues #7889, #9025 and #9379: Improvements to the random module. Raymond Hettinger <python@rcn.com> parents: 64511 diff changeset	210 return istart + istep*self._randbelow(n)
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	211
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	212 def randint(self, a, b):
16265 d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	213 """Return random integer in range [a, b], including both end points.
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	214 """
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	215
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	216 return self.randrange(a, b+1)
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	217
64553 d5331712b509 In the case where only a user supplied random() method is available, Raymond Hettinger <python@rcn.com> parents: 64532 diff changeset	218 def _randbelow(self, n, int=int, maxsize=1<<BPF, type=type,
64531 770c3ec05685 Minor refactoring and cleanup. Extend looping randrange() technique to subclasses. Raymond Hettinger <python@rcn.com> parents: 64523 diff changeset	219 Method=_MethodType, BuiltinMethod=_BuiltinMethodType):
64553 d5331712b509 In the case where only a user supplied random() method is available, Raymond Hettinger <python@rcn.com> parents: 64532 diff changeset	220 "Return a random int in the range [0,n). Raises ValueError if n==0."
30649 8841d34a2c37 SF bug #812202: randint is always even Raymond Hettinger <python@rcn.com> parents: 30346 diff changeset	221
85985 1f51867fe50e Issue #19169: Micro refactoring with a micro benefit for brevity and speed. Raymond Hettinger <python@rcn.com> parents: 85666 diff changeset	222 random = self.random
64516 6ba20b9039ae Small clean-ups. Raymond Hettinger <python@rcn.com> parents: 64512 diff changeset	223 getrandbits = self.getrandbits
6ba20b9039ae Small clean-ups. Raymond Hettinger <python@rcn.com> parents: 64512 diff changeset	224 # Only call self.getrandbits if the original random() builtin method
6ba20b9039ae Small clean-ups. Raymond Hettinger <python@rcn.com> parents: 64512 diff changeset	225 # has not been overridden or if a new getrandbits() was supplied.
85985 1f51867fe50e Issue #19169: Micro refactoring with a micro benefit for brevity and speed. Raymond Hettinger <python@rcn.com> parents: 85666 diff changeset	226 if type(random) is BuiltinMethod or type(getrandbits) is Method:
64553 d5331712b509 In the case where only a user supplied random() method is available, Raymond Hettinger <python@rcn.com> parents: 64532 diff changeset	227 k = n.bit_length() # don't use (n-1) here because n can be 1
64532 89fe5179aec5 Neaten-up comments and warning message. Raymond Hettinger <python@rcn.com> parents: 64531 diff changeset	228 r = getrandbits(k) # 0 <= r < 2**k
64516 6ba20b9039ae Small clean-ups. Raymond Hettinger <python@rcn.com> parents: 64512 diff changeset	229 while r >= n:
30649 8841d34a2c37 SF bug #812202: randint is always even Raymond Hettinger <python@rcn.com> parents: 30346 diff changeset	230 r = getrandbits(k)
64516 6ba20b9039ae Small clean-ups. Raymond Hettinger <python@rcn.com> parents: 64512 diff changeset	231 return r
64531 770c3ec05685 Minor refactoring and cleanup. Extend looping randrange() technique to subclasses. Raymond Hettinger <python@rcn.com> parents: 64523 diff changeset	232 # There's an overriden random() method but no new getrandbits() method,
770c3ec05685 Minor refactoring and cleanup. Extend looping randrange() technique to subclasses. Raymond Hettinger <python@rcn.com> parents: 64523 diff changeset	233 # so we can only use random() from here.
64553 d5331712b509 In the case where only a user supplied random() method is available, Raymond Hettinger <python@rcn.com> parents: 64532 diff changeset	234 if n >= maxsize:
30649 8841d34a2c37 SF bug #812202: randint is always even Raymond Hettinger <python@rcn.com> parents: 30346 diff changeset	235 _warn("Underlying random() generator does not supply \n"
64532 89fe5179aec5 Neaten-up comments and warning message. Raymond Hettinger <python@rcn.com> parents: 64531 diff changeset	236 "enough bits to choose from a population range this large.\n"
89fe5179aec5 Neaten-up comments and warning message. Raymond Hettinger <python@rcn.com> parents: 64531 diff changeset	237 "To remove the range limitation, add a getrandbits() method.")
64553 d5331712b509 In the case where only a user supplied random() method is available, Raymond Hettinger <python@rcn.com> parents: 64532 diff changeset	238 return int(random() * n)
d5331712b509 In the case where only a user supplied random() method is available, Raymond Hettinger <python@rcn.com> parents: 64532 diff changeset	239 rem = maxsize % n
d5331712b509 In the case where only a user supplied random() method is available, Raymond Hettinger <python@rcn.com> parents: 64532 diff changeset	240 limit = (maxsize - rem) / maxsize # int(limit * maxsize) % n == 0
d5331712b509 In the case where only a user supplied random() method is available, Raymond Hettinger <python@rcn.com> parents: 64532 diff changeset	241 r = random()
d5331712b509 In the case where only a user supplied random() method is available, Raymond Hettinger <python@rcn.com> parents: 64532 diff changeset	242 while r >= limit:
d5331712b509 In the case where only a user supplied random() method is available, Raymond Hettinger <python@rcn.com> parents: 64532 diff changeset	243 r = random()
d5331712b509 In the case where only a user supplied random() method is available, Raymond Hettinger <python@rcn.com> parents: 64532 diff changeset	244 return int(r*maxsize) % n
30649 8841d34a2c37 SF bug #812202: randint is always even Raymond Hettinger <python@rcn.com> parents: 30346 diff changeset	245
16265 d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	246 ## -------------------- sequence methods -------------------
d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	247
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	248 def choice(self, seq):
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	249 """Choose a random element from a non-empty sequence."""
64517 e83af141dffd Fix corner case for Random.choice() and add tests. Raymond Hettinger <python@rcn.com> parents: 64516 diff changeset	250 try:
e83af141dffd Fix corner case for Random.choice() and add tests. Raymond Hettinger <python@rcn.com> parents: 64516 diff changeset	251 i = self._randbelow(len(seq))
e83af141dffd Fix corner case for Random.choice() and add tests. Raymond Hettinger <python@rcn.com> parents: 64516 diff changeset	252 except ValueError:
e83af141dffd Fix corner case for Random.choice() and add tests. Raymond Hettinger <python@rcn.com> parents: 64516 diff changeset	253 raise IndexError('Cannot choose from an empty sequence')
e83af141dffd Fix corner case for Random.choice() and add tests. Raymond Hettinger <python@rcn.com> parents: 64516 diff changeset	254 return seq[i]
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	255
85988 0899960835f5 Minor clean-up of function parameters in random(). Raymond Hettinger <python@rcn.com> parents: 85661 diff changeset	256 def shuffle(self, x, random=None):
80230 58776cc74e89 Issue #15837: add some tests for random.shuffle(). Antoine Pitrou <solipsis@pitrou.net> parents: 77304 diff changeset	257 """Shuffle list x in place, and return None.
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	258
80230 58776cc74e89 Issue #15837: add some tests for random.shuffle(). Antoine Pitrou <solipsis@pitrou.net> parents: 77304 diff changeset	259 Optional argument random is a 0-argument function returning a
58776cc74e89 Issue #15837: add some tests for random.shuffle(). Antoine Pitrou <solipsis@pitrou.net> parents: 77304 diff changeset	260 random float in [0.0, 1.0); if it is the default None, the
58776cc74e89 Issue #15837: add some tests for random.shuffle(). Antoine Pitrou <solipsis@pitrou.net> parents: 77304 diff changeset	261 standard random.random will be used.
85661 4782faf29480 Improve the docstring of random.shuffle. Inform users not to provide int arg. Senthil Kumaran <senthil@uthcode.com> parents: 85418 diff changeset	262
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	263 """
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	264
85988 0899960835f5 Minor clean-up of function parameters in random(). Raymond Hettinger <python@rcn.com> parents: 85661 diff changeset	265 if random is None:
0899960835f5 Minor clean-up of function parameters in random(). Raymond Hettinger <python@rcn.com> parents: 85661 diff changeset	266 randbelow = self._randbelow
0899960835f5 Minor clean-up of function parameters in random(). Raymond Hettinger <python@rcn.com> parents: 85661 diff changeset	267 for i in reversed(range(1, len(x))):
0899960835f5 Minor clean-up of function parameters in random(). Raymond Hettinger <python@rcn.com> parents: 85661 diff changeset	268 # pick an element in x[:i+1] with which to exchange x[i]
0899960835f5 Minor clean-up of function parameters in random(). Raymond Hettinger <python@rcn.com> parents: 85661 diff changeset	269 j = randbelow(i+1)
0899960835f5 Minor clean-up of function parameters in random(). Raymond Hettinger <python@rcn.com> parents: 85661 diff changeset	270 x[i], x[j] = x[j], x[i]
0899960835f5 Minor clean-up of function parameters in random(). Raymond Hettinger <python@rcn.com> parents: 85661 diff changeset	271 else:
0899960835f5 Minor clean-up of function parameters in random(). Raymond Hettinger <python@rcn.com> parents: 85661 diff changeset	272 _int = int
0899960835f5 Minor clean-up of function parameters in random(). Raymond Hettinger <python@rcn.com> parents: 85661 diff changeset	273 for i in reversed(range(1, len(x))):
0899960835f5 Minor clean-up of function parameters in random(). Raymond Hettinger <python@rcn.com> parents: 85661 diff changeset	274 # pick an element in x[:i+1] with which to exchange x[i]
0899960835f5 Minor clean-up of function parameters in random(). Raymond Hettinger <python@rcn.com> parents: 85661 diff changeset	275 j = _int(random() * (i+1))
0899960835f5 Minor clean-up of function parameters in random(). Raymond Hettinger <python@rcn.com> parents: 85661 diff changeset	276 x[i], x[j] = x[j], x[i]
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	277
29430 b80a22250e4f SF bug #753602: random.sample not properly documented Raymond Hettinger <python@rcn.com> parents: 29250 diff changeset	278 def sample(self, population, k):
44665 91928d99ebb0 Take Tim's advice and have random.sample() support only sequences and sets. Raymond Hettinger <python@rcn.com> parents: 44662 diff changeset	279 """Chooses k unique random elements from a population sequence or set.
26155 8ceb455f5541 SF patch 629637: Add sample(population, k) method to the random module. Raymond Hettinger <python@rcn.com> parents: 24861 diff changeset	280
26178 83ae4a902df0 Improved clarity and thoroughness of docstring. Raymond Hettinger <python@rcn.com> parents: 26172 diff changeset	281 Returns a new list containing elements from the population while
83ae4a902df0 Improved clarity and thoroughness of docstring. Raymond Hettinger <python@rcn.com> parents: 26172 diff changeset	282 leaving the original population unchanged. The resulting list is
83ae4a902df0 Improved clarity and thoroughness of docstring. Raymond Hettinger <python@rcn.com> parents: 26172 diff changeset	283 in selection order so that all sub-slices will also be valid random
83ae4a902df0 Improved clarity and thoroughness of docstring. Raymond Hettinger <python@rcn.com> parents: 26172 diff changeset	284 samples. This allows raffle winners (the sample) to be partitioned
83ae4a902df0 Improved clarity and thoroughness of docstring. Raymond Hettinger <python@rcn.com> parents: 26172 diff changeset	285 into grand prize and second place winners (the subslices).
26155 8ceb455f5541 SF patch 629637: Add sample(population, k) method to the random module. Raymond Hettinger <python@rcn.com> parents: 24861 diff changeset	286
26178 83ae4a902df0 Improved clarity and thoroughness of docstring. Raymond Hettinger <python@rcn.com> parents: 26172 diff changeset	287 Members of the population need not be hashable or unique. If the
83ae4a902df0 Improved clarity and thoroughness of docstring. Raymond Hettinger <python@rcn.com> parents: 26172 diff changeset	288 population contains repeats, then each occurrence is a possible
83ae4a902df0 Improved clarity and thoroughness of docstring. Raymond Hettinger <python@rcn.com> parents: 26172 diff changeset	289 selection in the sample.
26155 8ceb455f5541 SF patch 629637: Add sample(population, k) method to the random module. Raymond Hettinger <python@rcn.com> parents: 24861 diff changeset	290
41642 a6eb6acfe04a Merged revisions 55007-55179 via svnmerge from Guido van Rossum <guido@python.org> parents: 41592 diff changeset	291 To choose a sample in a range of integers, use range as an argument.
26178 83ae4a902df0 Improved clarity and thoroughness of docstring. Raymond Hettinger <python@rcn.com> parents: 26172 diff changeset	292 This is especially fast and space efficient for sampling from a
41642 a6eb6acfe04a Merged revisions 55007-55179 via svnmerge from Guido van Rossum <guido@python.org> parents: 41592 diff changeset	293 large population: sample(range(10000000), 60)
26155 8ceb455f5541 SF patch 629637: Add sample(population, k) method to the random module. Raymond Hettinger <python@rcn.com> parents: 24861 diff changeset	294 """
8ceb455f5541 SF patch 629637: Add sample(population, k) method to the random module. Raymond Hettinger <python@rcn.com> parents: 24861 diff changeset	295
26178 83ae4a902df0 Improved clarity and thoroughness of docstring. Raymond Hettinger <python@rcn.com> parents: 26172 diff changeset	296 # Sampling without replacement entails tracking either potential
35359 c5bf5685267b Implement random.sample() using sets instead of dicts. Raymond Hettinger <python@rcn.com> parents: 34942 diff changeset	297 # selections (the pool) in a list or previous selections in a set.
26178 83ae4a902df0 Improved clarity and thoroughness of docstring. Raymond Hettinger <python@rcn.com> parents: 26172 diff changeset	298
31578 8183dd1a4fe6 Reflow long line. Jeremy Hylton <jeremy@alum.mit.edu> parents: 31389 diff changeset	299 # When the number of selections is small compared to the
8183dd1a4fe6 Reflow long line. Jeremy Hylton <jeremy@alum.mit.edu> parents: 31389 diff changeset	300 # population, then tracking selections is efficient, requiring
35359 c5bf5685267b Implement random.sample() using sets instead of dicts. Raymond Hettinger <python@rcn.com> parents: 34942 diff changeset	301 # only a small set and an occasional reselection. For
31578 8183dd1a4fe6 Reflow long line. Jeremy Hylton <jeremy@alum.mit.edu> parents: 31389 diff changeset	302 # a larger number of selections, the pool tracking method is
8183dd1a4fe6 Reflow long line. Jeremy Hylton <jeremy@alum.mit.edu> parents: 31389 diff changeset	303 # preferred since the list takes less space than the
35359 c5bf5685267b Implement random.sample() using sets instead of dicts. Raymond Hettinger <python@rcn.com> parents: 34942 diff changeset	304 # set and it doesn't suffer from frequent reselections.
26178 83ae4a902df0 Improved clarity and thoroughness of docstring. Raymond Hettinger <python@rcn.com> parents: 26172 diff changeset	305
69859 e2f7db1255df Sync-up minor code edits with the default branch. Raymond Hettinger <python@rcn.com> parents: 69857 diff changeset	306 if isinstance(population, _Set):
44665 91928d99ebb0 Take Tim's advice and have random.sample() support only sequences and sets. Raymond Hettinger <python@rcn.com> parents: 44662 diff changeset	307 population = tuple(population)
69859 e2f7db1255df Sync-up minor code edits with the default branch. Raymond Hettinger <python@rcn.com> parents: 69857 diff changeset	308 if not isinstance(population, _Sequence):
e2f7db1255df Sync-up minor code edits with the default branch. Raymond Hettinger <python@rcn.com> parents: 69857 diff changeset	309 raise TypeError("Population must be a sequence or set. For dicts, use list(d).")
64531 770c3ec05685 Minor refactoring and cleanup. Extend looping randrange() technique to subclasses. Raymond Hettinger <python@rcn.com> parents: 64523 diff changeset	310 randbelow = self._randbelow
26155 8ceb455f5541 SF patch 629637: Add sample(population, k) method to the random module. Raymond Hettinger <python@rcn.com> parents: 24861 diff changeset	311 n = len(population)
8ceb455f5541 SF patch 629637: Add sample(population, k) method to the random module. Raymond Hettinger <python@rcn.com> parents: 24861 diff changeset	312 if not 0 <= k <= n:
44665 91928d99ebb0 Take Tim's advice and have random.sample() support only sequences and sets. Raymond Hettinger <python@rcn.com> parents: 44662 diff changeset	313 raise ValueError("Sample larger than population")
26178 83ae4a902df0 Improved clarity and thoroughness of docstring. Raymond Hettinger <python@rcn.com> parents: 26172 diff changeset	314 result = [None] * k
35359 c5bf5685267b Implement random.sample() using sets instead of dicts. Raymond Hettinger <python@rcn.com> parents: 34942 diff changeset	315 setsize = 21 # size of a small set minus size of an empty list
c5bf5685267b Implement random.sample() using sets instead of dicts. Raymond Hettinger <python@rcn.com> parents: 34942 diff changeset	316 if k > 5:
35465 3e5c07faab11 Whitespace normalization (via reindent.py). Tim Peters <tim.peters@gmail.com> parents: 35359 diff changeset	317 setsize += 4 ** _ceil(_log(k * 3, 4)) # table size for big sets
44665 91928d99ebb0 Take Tim's advice and have random.sample() support only sequences and sets. Raymond Hettinger <python@rcn.com> parents: 44662 diff changeset	318 if n <= setsize:
91928d99ebb0 Take Tim's advice and have random.sample() support only sequences and sets. Raymond Hettinger <python@rcn.com> parents: 44662 diff changeset	319 # An n-length list is smaller than a k-length set
26266 42279f7d244d Improve comments. Clarify docs. Raymond Hettinger <python@rcn.com> parents: 26178 diff changeset	320 pool = list(population)
41642 a6eb6acfe04a Merged revisions 55007-55179 via svnmerge from Guido van Rossum <guido@python.org> parents: 41592 diff changeset	321 for i in range(k): # invariant: non-selected at [0,n-i)
64531 770c3ec05685 Minor refactoring and cleanup. Extend looping randrange() technique to subclasses. Raymond Hettinger <python@rcn.com> parents: 64523 diff changeset	322 j = randbelow(n-i)
26266 42279f7d244d Improve comments. Clarify docs. Raymond Hettinger <python@rcn.com> parents: 26178 diff changeset	323 result[i] = pool[j]
27080 2ae1d17572da Remove the random=None nonsense from sample() before it gets set in stone. Raymond Hettinger <python@rcn.com> parents: 26829 diff changeset	324 pool[j] = pool[n-i-1] # move non-selected item into vacancy
26178 83ae4a902df0 Improved clarity and thoroughness of docstring. Raymond Hettinger <python@rcn.com> parents: 26172 diff changeset	325 else:
44665 91928d99ebb0 Take Tim's advice and have random.sample() support only sequences and sets. Raymond Hettinger <python@rcn.com> parents: 44662 diff changeset	326 selected = set()
91928d99ebb0 Take Tim's advice and have random.sample() support only sequences and sets. Raymond Hettinger <python@rcn.com> parents: 44662 diff changeset	327 selected_add = selected.add
91928d99ebb0 Take Tim's advice and have random.sample() support only sequences and sets. Raymond Hettinger <python@rcn.com> parents: 44662 diff changeset	328 for i in range(k):
64531 770c3ec05685 Minor refactoring and cleanup. Extend looping randrange() technique to subclasses. Raymond Hettinger <python@rcn.com> parents: 64523 diff changeset	329 j = randbelow(n)
44665 91928d99ebb0 Take Tim's advice and have random.sample() support only sequences and sets. Raymond Hettinger <python@rcn.com> parents: 44662 diff changeset	330 while j in selected:
64531 770c3ec05685 Minor refactoring and cleanup. Extend looping randrange() technique to subclasses. Raymond Hettinger <python@rcn.com> parents: 64523 diff changeset	331 j = randbelow(n)
44665 91928d99ebb0 Take Tim's advice and have random.sample() support only sequences and sets. Raymond Hettinger <python@rcn.com> parents: 44662 diff changeset	332 selected_add(j)
91928d99ebb0 Take Tim's advice and have random.sample() support only sequences and sets. Raymond Hettinger <python@rcn.com> parents: 44662 diff changeset	333 result[i] = population[j]
26266 42279f7d244d Improve comments. Clarify docs. Raymond Hettinger <python@rcn.com> parents: 26178 diff changeset	334 return result
26155 8ceb455f5541 SF patch 629637: Add sample(population, k) method to the random module. Raymond Hettinger <python@rcn.com> parents: 24861 diff changeset	335
16265 d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	336 ## -------------------- real-valued distributions -------------------
d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	337
d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	338 ## -------------------- uniform distribution -------------------
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	339
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	340 def uniform(self, a, b):
54705 0e1b3c24d3e2 Issue 6261: Clarify behavior of random.uniform(). Raymond Hettinger <python@rcn.com> parents: 51834 diff changeset	341 "Get a random number in the range [a, b) or [a, b] depending on rounding."
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	342 return a + (b-a) * self.random()
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	343
46034 0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	344 ## -------------------- triangular --------------------
0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	345
0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	346 def triangular(self, low=0.0, high=1.0, mode=None):
0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	347 """Triangular distribution.
0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	348
0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	349 Continuous distribution bounded by given lower and upper limits,
0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	350 and having a given mode value in-between.
0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	351
0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	352 http://en.wikipedia.org/wiki/Triangular_distribution
0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	353
0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	354 """
0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	355 u = self.random()
0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	356 c = 0.5 if mode is None else (mode - low) / (high - low)
0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	357 if u > c:
0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	358 u = 1.0 - u
0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	359 c = 1.0 - c
0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	360 low, high = high, low
0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	361 return low + (high - low) * (u * c) ** 0.5
0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	362
16265 d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	363 ## -------------------- normal distribution --------------------
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	364
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	365 def normalvariate(self, mu, sigma):
23531 a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	366 """Normal distribution.
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	367
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	368 mu is the mean, and sigma is the standard deviation.
23536 0a4c92559a0b Whitespace normalized. Raymond Hettinger <python@rcn.com> parents: 23531 diff changeset	369
23531 a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	370 """
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	371 # mu = mean, sigma = standard deviation
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	372
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	373 # Uses Kinderman and Monahan method. Reference: Kinderman,
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	374 # A.J. and Monahan, J.F., "Computer generation of random
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	375 # variables using the ratio of uniform deviates", ACM Trans
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	376 # Math Software, 3, (1977), pp257-260.
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	377
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	378 random = self.random
34942 7287b41145ae SF patch #1191489: Simplify logic in random.py Raymond Hettinger <python@rcn.com> parents: 34312 diff changeset	379 while 1:
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	380 u1 = random()
27085 90350b5d3397 Correct long standing bugs in the methods for random distributions. Raymond Hettinger <python@rcn.com> parents: 27080 diff changeset	381 u2 = 1.0 - random()
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	382 z = NV_MAGICCONST*(u1-0.5)/u2
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	383 zz = z*z/4.0
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	384 if zz <= -_log(u2):
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	385 break
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	386 return mu + z*sigma
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	387
16265 d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	388 ## -------------------- lognormal distribution --------------------
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	389
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	390 def lognormvariate(self, mu, sigma):
23531 a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	391 """Log normal distribution.
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	392
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	393 If you take the natural logarithm of this distribution, you'll get a
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	394 normal distribution with mean mu and standard deviation sigma.
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	395 mu can have any value, and sigma must be greater than zero.
23536 0a4c92559a0b Whitespace normalized. Raymond Hettinger <python@rcn.com> parents: 23531 diff changeset	396
23531 a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	397 """
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	398 return _exp(self.normalvariate(mu, sigma))
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	399
16265 d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	400 ## -------------------- exponential distribution --------------------
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	401
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	402 def expovariate(self, lambd):
23531 a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	403 """Exponential distribution.
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	404
50626 fed2ae1e50c2 Merged revisions 68378 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48596 diff changeset	405 lambd is 1.0 divided by the desired mean. It should be
fed2ae1e50c2 Merged revisions 68378 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48596 diff changeset	406 nonzero. (The parameter would be called "lambda", but that is
fed2ae1e50c2 Merged revisions 68378 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48596 diff changeset	407 a reserved word in Python.) Returned values range from 0 to
fed2ae1e50c2 Merged revisions 68378 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48596 diff changeset	408 positive infinity if lambd is positive, and from negative
fed2ae1e50c2 Merged revisions 68378 via svnmerge from Mark Dickinson <dickinsm@gmail.com> parents: 48596 diff changeset	409 infinity to 0 if lambd is negative.
23536 0a4c92559a0b Whitespace normalized. Raymond Hettinger <python@rcn.com> parents: 23531 diff changeset	410
23531 a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	411 """
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	412 # lambd: rate lambd = 1/mean
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	413 # ('lambda' is a Python reserved word)
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	414
70949 9216e0a5d950 Code simplification suggested by Sven Marnach. Raymond Hettinger <python@rcn.com> parents: 69859 diff changeset	415 # we use 1-random() instead of random() to preclude the
9216e0a5d950 Code simplification suggested by Sven Marnach. Raymond Hettinger <python@rcn.com> parents: 69859 diff changeset	416 # possibility of taking the log of zero.
9216e0a5d950 Code simplification suggested by Sven Marnach. Raymond Hettinger <python@rcn.com> parents: 69859 diff changeset	417 return -_log(1.0 - self.random())/lambd
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	418
16265 d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	419 ## -------------------- von Mises distribution --------------------
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	420
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	421 def vonmisesvariate(self, mu, kappa):
23531 a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	422 """Circular data distribution.
23536 0a4c92559a0b Whitespace normalized. Raymond Hettinger <python@rcn.com> parents: 23531 diff changeset	423
23531 a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	424 mu is the mean angle, expressed in radians between 0 and 2*pi, and
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	425 kappa is the concentration parameter, which must be greater than or
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	426 equal to zero. If kappa is equal to zero, this distribution reduces
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	427 to a uniform random angle over the range 0 to 2*pi.
23536 0a4c92559a0b Whitespace normalized. Raymond Hettinger <python@rcn.com> parents: 23531 diff changeset	428
23531 a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	429 """
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	430 # mu: mean angle (in radians between 0 and 2*pi)
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	431 # kappa: concentration parameter kappa (>= 0)
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	432 # if kappa = 0 generate uniform random angle
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	433
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	434 # Based upon an algorithm published in: Fisher, N.I.,
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	435 # "Statistical Analysis of Circular Data", Cambridge
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	436 # University Press, 1993.
7881 6370f1593c72 Correction to vonmisesvariate() by Magnus Kessler: it should take and Guido van Rossum <guido@python.org> parents: 7412 diff changeset	437
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	438 # Thanks to Magnus Kessler for a correction to the
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	439 # implementation of step 4.
7881 6370f1593c72 Correction to vonmisesvariate() by Magnus Kessler: it should take and Guido van Rossum <guido@python.org> parents: 7412 diff changeset	440
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	441 random = self.random
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	442 if kappa <= 1e-6:
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	443 return TWOPI * random()
7881 6370f1593c72 Correction to vonmisesvariate() by Magnus Kessler: it should take and Guido van Rossum <guido@python.org> parents: 7412 diff changeset	444
82140 d94b73c95646 Issue #17141: random.vonmisesvariate() no more hangs for large kappas. Serhiy Storchaka <storchaka@gmail.com> parents: 82130 diff changeset	445 s = 0.5 / kappa
d94b73c95646 Issue #17141: random.vonmisesvariate() no more hangs for large kappas. Serhiy Storchaka <storchaka@gmail.com> parents: 82130 diff changeset	446 r = s + _sqrt(1.0 + s * s)
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	447
34942 7287b41145ae SF patch #1191489: Simplify logic in random.py Raymond Hettinger <python@rcn.com> parents: 34312 diff changeset	448 while 1:
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	449 u1 = random()
82140 d94b73c95646 Issue #17141: random.vonmisesvariate() no more hangs for large kappas. Serhiy Storchaka <storchaka@gmail.com> parents: 82130 diff changeset	450 z = _cos(_pi * u1)
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	451
82140 d94b73c95646 Issue #17141: random.vonmisesvariate() no more hangs for large kappas. Serhiy Storchaka <storchaka@gmail.com> parents: 82130 diff changeset	452 d = z / (r + z)
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	453 u2 = random()
82140 d94b73c95646 Issue #17141: random.vonmisesvariate() no more hangs for large kappas. Serhiy Storchaka <storchaka@gmail.com> parents: 82130 diff changeset	454 if u2 < 1.0 - d * d or u2 <= (1.0 - d) * _exp(d):
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	455 break
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	456
82140 d94b73c95646 Issue #17141: random.vonmisesvariate() no more hangs for large kappas. Serhiy Storchaka <storchaka@gmail.com> parents: 82130 diff changeset	457 q = 1.0 / r
d94b73c95646 Issue #17141: random.vonmisesvariate() no more hangs for large kappas. Serhiy Storchaka <storchaka@gmail.com> parents: 82130 diff changeset	458 f = (q + z) / (1.0 + q * z)
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	459 u3 = random()
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	460 if u3 > 0.5:
82130 41e97652a9f9 Issue #17149: Fix random.vonmisesvariate to always return results in [0, 2math.pi]. Mark Dickinson <dickinsm@gmail.com>* parents: 77303 diff changeset	461 theta = (mu + _acos(f)) % TWOPI
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	462 else:
82130 41e97652a9f9 Issue #17149: Fix random.vonmisesvariate to always return results in [0, 2math.pi]. Mark Dickinson <dickinsm@gmail.com>* parents: 77303 diff changeset	463 theta = (mu - _acos(f)) % TWOPI
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	464
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	465 return theta
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	466
16265 d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	467 ## -------------------- gamma distribution --------------------
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	468
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	469 def gammavariate(self, alpha, beta):
23531 a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	470 """Gamma distribution. Not the gamma function!
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	471
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	472 Conditions on the parameters are alpha > 0 and beta > 0.
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	473
68846 e880020e7e6a Issue 10787: Document the probability density function for random.gammavariate. Raymond Hettinger <python@rcn.com> parents: 57584 diff changeset	474 The probability distribution function is:
e880020e7e6a Issue 10787: Document the probability density function for random.gammavariate. Raymond Hettinger <python@rcn.com> parents: 57584 diff changeset	475
e880020e7e6a Issue 10787: Document the probability density function for random.gammavariate. Raymond Hettinger <python@rcn.com> parents: 57584 diff changeset	476 x ** (alpha - 1) * math.exp(-x / beta)
e880020e7e6a Issue 10787: Document the probability density function for random.gammavariate. Raymond Hettinger <python@rcn.com> parents: 57584 diff changeset	477 pdf(x) = --------------------------------------
e880020e7e6a Issue 10787: Document the probability density function for random.gammavariate. Raymond Hettinger <python@rcn.com> parents: 57584 diff changeset	478 math.gamma(alpha) * beta ** alpha
e880020e7e6a Issue 10787: Document the probability density function for random.gammavariate. Raymond Hettinger <python@rcn.com> parents: 57584 diff changeset	479
23531 a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	480 """
23521 a90faa5f9417 Whitespace normalization. Tim Peters <tim.peters@gmail.com> parents: 23451 diff changeset	481
23447 08ccb0f3e2d4 Closes patch 529408 deprecating random.stdgamma(). Raymond Hettinger <python@rcn.com> parents: 23442 diff changeset	482 # alpha > 0, beta > 0, mean is alphabeta, variance is alphabeta**2
23521 a90faa5f9417 Whitespace normalization. Tim Peters <tim.peters@gmail.com> parents: 23451 diff changeset	483
23451 273dd2508c57 Use spaces, not tabs for indents. Guido van Rossum <guido@python.org> parents: 23447 diff changeset	484 # Warning: a few older sources define the gamma distribution in terms
273dd2508c57 Use spaces, not tabs for indents. Guido van Rossum <guido@python.org> parents: 23447 diff changeset	485 # of alpha > -1.0
273dd2508c57 Use spaces, not tabs for indents. Guido van Rossum <guido@python.org> parents: 23447 diff changeset	486 if alpha <= 0.0 or beta <= 0.0:
43020 907a45df1295 Raise statement normalization in Lib/. Collin Winter <collinw@gmail.com> parents: 42084 diff changeset	487 raise ValueError('gammavariate: alpha and beta must be > 0.0')
23521 a90faa5f9417 Whitespace normalization. Tim Peters <tim.peters@gmail.com> parents: 23451 diff changeset	488
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	489 random = self.random
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	490 if alpha > 1.0:
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	491
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	492 # Uses R.C.H. Cheng, "The generation of Gamma
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	493 # variables with non-integral shape parameters",
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	494 # Applied Statistics, (1977), 26, No. 1, p71-74
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	495
23442 b15896053933 Closes SF bug 527139. Moved temp variables inside guard. Raymond Hettinger <python@rcn.com> parents: 23380 diff changeset	496 ainv = _sqrt(2.0 * alpha - 1.0)
b15896053933 Closes SF bug 527139. Moved temp variables inside guard. Raymond Hettinger <python@rcn.com> parents: 23380 diff changeset	497 bbb = alpha - LOG4
b15896053933 Closes SF bug 527139. Moved temp variables inside guard. Raymond Hettinger <python@rcn.com> parents: 23380 diff changeset	498 ccc = alpha + ainv
23521 a90faa5f9417 Whitespace normalization. Tim Peters <tim.peters@gmail.com> parents: 23451 diff changeset	499
34942 7287b41145ae SF patch #1191489: Simplify logic in random.py Raymond Hettinger <python@rcn.com> parents: 34312 diff changeset	500 while 1:
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	501 u1 = random()
27085 90350b5d3397 Correct long standing bugs in the methods for random distributions. Raymond Hettinger <python@rcn.com> parents: 27080 diff changeset	502 if not 1e-7 < u1 < .9999999:
90350b5d3397 Correct long standing bugs in the methods for random distributions. Raymond Hettinger <python@rcn.com> parents: 27080 diff changeset	503 continue
90350b5d3397 Correct long standing bugs in the methods for random distributions. Raymond Hettinger <python@rcn.com> parents: 27080 diff changeset	504 u2 = 1.0 - random()
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	505 v = _log(u1/(1.0-u1))/ainv
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	506 x = alpha*_exp(v)
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	507 z = u1u1u2
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	508 r = bbb+ccc*v-x
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	509 if r + SG_MAGICCONST - 4.5*z >= 0.0 or r >= _log(z):
23447 08ccb0f3e2d4 Closes patch 529408 deprecating random.stdgamma(). Raymond Hettinger <python@rcn.com> parents: 23442 diff changeset	510 return x * beta
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	511
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	512 elif alpha == 1.0:
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	513 # expovariate(1)
15871 62aeefa01fdd Whitespace normalization. Tim Peters <tim.peters@gmail.com> parents: 14617 diff changeset	514 u = random()
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	515 while u <= 1e-7:
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	516 u = random()
23447 08ccb0f3e2d4 Closes patch 529408 deprecating random.stdgamma(). Raymond Hettinger <python@rcn.com> parents: 23442 diff changeset	517 return -_log(u) * beta
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	518
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	519 else: # alpha is between 0 and 1 (exclusive)
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	520
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	521 # Uses ALGORITHM GS of Statistical Computing - Kennedy & Gentle
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	522
34942 7287b41145ae SF patch #1191489: Simplify logic in random.py Raymond Hettinger <python@rcn.com> parents: 34312 diff changeset	523 while 1:
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	524 u = random()
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	525 b = (_e + alpha)/_e
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	526 p = b*u
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	527 if p <= 1.0:
34942 7287b41145ae SF patch #1191489: Simplify logic in random.py Raymond Hettinger <python@rcn.com> parents: 34312 diff changeset	528 x = p ** (1.0/alpha)
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	529 else:
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	530 x = -_log((b-p)/alpha)
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	531 u1 = random()
34942 7287b41145ae SF patch #1191489: Simplify logic in random.py Raymond Hettinger <python@rcn.com> parents: 34312 diff changeset	532 if p > 1.0:
7287b41145ae SF patch #1191489: Simplify logic in random.py Raymond Hettinger <python@rcn.com> parents: 34312 diff changeset	533 if u1 <= x ** (alpha - 1.0):
7287b41145ae SF patch #1191489: Simplify logic in random.py Raymond Hettinger <python@rcn.com> parents: 34312 diff changeset	534 break
7287b41145ae SF patch #1191489: Simplify logic in random.py Raymond Hettinger <python@rcn.com> parents: 34312 diff changeset	535 elif u1 <= _exp(-x):
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	536 break
23447 08ccb0f3e2d4 Closes patch 529408 deprecating random.stdgamma(). Raymond Hettinger <python@rcn.com> parents: 23442 diff changeset	537 return x * beta
08ccb0f3e2d4 Closes patch 529408 deprecating random.stdgamma(). Raymond Hettinger <python@rcn.com> parents: 23442 diff changeset	538
16265 d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	539 ## -------------------- Gauss (faster alternative) --------------------
1576 695fb494a3a2 Added gauss() (same as normal but twice as fast) and betavariate(); Guido van Rossum <guido@python.org> parents: 1575 diff changeset	540
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	541 def gauss(self, mu, sigma):
23531 a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	542 """Gaussian distribution.
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	543
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	544 mu is the mean, and sigma is the standard deviation. This is
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	545 slightly faster than the normalvariate() function.
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	546
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	547 Not thread-safe without a lock around calls.
23536 0a4c92559a0b Whitespace normalized. Raymond Hettinger <python@rcn.com> parents: 23531 diff changeset	548
23531 a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	549 """
1577 444e349f962f Use float constants directly; cosmetic changes; initialize largest Guido van Rossum <guido@python.org> parents: 1576 diff changeset	550
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	551 # When x and y are two variables from [0, 1), uniformly
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	552 # distributed, then
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	553 #
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	554 # cos(2pix)sqrt(-2log(1-y))
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	555 # sin(2pix)sqrt(-2log(1-y))
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	556 #
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	557 # are two independent variables with normal distribution
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	558 # (mu = 0, sigma = 1).
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	559 # (Lambert Meertens)
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	560 # (corrected version; bug discovered by Mike Miller, fixed by LM)
1577 444e349f962f Use float constants directly; cosmetic changes; initialize largest Guido van Rossum <guido@python.org> parents: 1576 diff changeset	561
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	562 # Multithreading note: When two threads call this function
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	563 # simultaneously, it is possible that they will receive the
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	564 # same return value. The window is very small though. To
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	565 # avoid this, you have to use a lock around all calls. (I
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	566 # didn't want to slow this down in the serial case by using a
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	567 # lock here.)
1577 444e349f962f Use float constants directly; cosmetic changes; initialize largest Guido van Rossum <guido@python.org> parents: 1576 diff changeset	568
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	569 random = self.random
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	570 z = self.gauss_next
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	571 self.gauss_next = None
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	572 if z is None:
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	573 x2pi = random() * TWOPI
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	574 g2rad = _sqrt(-2.0 * _log(1.0 - random()))
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	575 z = _cos(x2pi) * g2rad
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	576 self.gauss_next = _sin(x2pi) * g2rad
1577 444e349f962f Use float constants directly; cosmetic changes; initialize largest Guido van Rossum <guido@python.org> parents: 1576 diff changeset	577
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	578 return mu + z*sigma
1576 695fb494a3a2 Added gauss() (same as normal but twice as fast) and betavariate(); Guido van Rossum <guido@python.org> parents: 1575 diff changeset	579
16265 d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	580 ## -------------------- beta --------------------
16271 7ef2382f6123 SF bug 130030: Claim of bad betavariate algorithm. Tim Peters <tim.peters@gmail.com> parents: 16265 diff changeset	581 ## See
69362 f5b9ad73157c #11848: replace dead link in random.betavariate comment. Ezio Melotti <ezio.melotti@gmail.com> parents: 68846 diff changeset	582 ## http://mail.python.org/pipermail/python-bugs-list/2001-January/003752.html
16271 7ef2382f6123 SF bug 130030: Claim of bad betavariate algorithm. Tim Peters <tim.peters@gmail.com> parents: 16265 diff changeset	583 ## for Ivan Frohne's insightful analysis of why the original implementation:
7ef2382f6123 SF bug 130030: Claim of bad betavariate algorithm. Tim Peters <tim.peters@gmail.com> parents: 16265 diff changeset	584 ##
7ef2382f6123 SF bug 130030: Claim of bad betavariate algorithm. Tim Peters <tim.peters@gmail.com> parents: 16265 diff changeset	585 ## def betavariate(self, alpha, beta):
7ef2382f6123 SF bug 130030: Claim of bad betavariate algorithm. Tim Peters <tim.peters@gmail.com> parents: 16265 diff changeset	586 ## # Discrete Event Simulation in C, pp 87-88.
7ef2382f6123 SF bug 130030: Claim of bad betavariate algorithm. Tim Peters <tim.peters@gmail.com> parents: 16265 diff changeset	587 ##
7ef2382f6123 SF bug 130030: Claim of bad betavariate algorithm. Tim Peters <tim.peters@gmail.com> parents: 16265 diff changeset	588 ## y = self.expovariate(alpha)
7ef2382f6123 SF bug 130030: Claim of bad betavariate algorithm. Tim Peters <tim.peters@gmail.com> parents: 16265 diff changeset	589 ## z = self.expovariate(1.0/beta)
7ef2382f6123 SF bug 130030: Claim of bad betavariate algorithm. Tim Peters <tim.peters@gmail.com> parents: 16265 diff changeset	590 ## return z/(y+z)
7ef2382f6123 SF bug 130030: Claim of bad betavariate algorithm. Tim Peters <tim.peters@gmail.com> parents: 16265 diff changeset	591 ##
7ef2382f6123 SF bug 130030: Claim of bad betavariate algorithm. Tim Peters <tim.peters@gmail.com> parents: 16265 diff changeset	592 ## was dead wrong, and how it probably got that way.
1576 695fb494a3a2 Added gauss() (same as normal but twice as fast) and betavariate(); Guido van Rossum <guido@python.org> parents: 1575 diff changeset	593
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	594 def betavariate(self, alpha, beta):
23531 a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	595 """Beta distribution.
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	596
40737 6ebad2a6b990 Merged revisions 53451-53537 via svnmerge from Thomas Wouters <thomas@python.org> parents: 40644 diff changeset	597 Conditions on the parameters are alpha > 0 and beta > 0.
23531 a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	598 Returned values range between 0 and 1.
23536 0a4c92559a0b Whitespace normalized. Raymond Hettinger <python@rcn.com> parents: 23531 diff changeset	599
23531 a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	600 """
23536 0a4c92559a0b Whitespace normalized. Raymond Hettinger <python@rcn.com> parents: 23531 diff changeset	601
16271 7ef2382f6123 SF bug 130030: Claim of bad betavariate algorithm. Tim Peters <tim.peters@gmail.com> parents: 16265 diff changeset	602 # This version due to Janne Sinkkonen, and matches all the std
7ef2382f6123 SF bug 130030: Claim of bad betavariate algorithm. Tim Peters <tim.peters@gmail.com> parents: 16265 diff changeset	603 # texts (e.g., Knuth Vol 2 Ed 3 pg 134 "the beta distribution").
7ef2382f6123 SF bug 130030: Claim of bad betavariate algorithm. Tim Peters <tim.peters@gmail.com> parents: 16265 diff changeset	604 y = self.gammavariate(alpha, 1.)
7ef2382f6123 SF bug 130030: Claim of bad betavariate algorithm. Tim Peters <tim.peters@gmail.com> parents: 16265 diff changeset	605 if y == 0:
7ef2382f6123 SF bug 130030: Claim of bad betavariate algorithm. Tim Peters <tim.peters@gmail.com> parents: 16265 diff changeset	606 return 0.0
7ef2382f6123 SF bug 130030: Claim of bad betavariate algorithm. Tim Peters <tim.peters@gmail.com> parents: 16265 diff changeset	607 else:
7ef2382f6123 SF bug 130030: Claim of bad betavariate algorithm. Tim Peters <tim.peters@gmail.com> parents: 16265 diff changeset	608 return y / (y + self.gammavariate(beta, 1.))
1576 695fb494a3a2 Added gauss() (same as normal but twice as fast) and betavariate(); Guido van Rossum <guido@python.org> parents: 1575 diff changeset	609
16265 d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	610 ## -------------------- Pareto --------------------
6698 b73eb4e6face Added Pareto and Weibull distributions, courtesy Jeremy Hylton. Guido van Rossum <guido@python.org> parents: 1618 diff changeset	611
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	612 def paretovariate(self, alpha):
23531 a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	613 """Pareto distribution. alpha is the shape parameter."""
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	614 # Jain, pg. 495
6698 b73eb4e6face Added Pareto and Weibull distributions, courtesy Jeremy Hylton. Guido van Rossum <guido@python.org> parents: 1618 diff changeset	615
27085 90350b5d3397 Correct long standing bugs in the methods for random distributions. Raymond Hettinger <python@rcn.com> parents: 27080 diff changeset	616 u = 1.0 - self.random()
64568 7c2eb5b6cc58 One more conversion from pow() to *. Raymond Hettinger <python@rcn.com>* parents: 64567 diff changeset	617 return 1.0 / u ** (1.0/alpha)
6698 b73eb4e6face Added Pareto and Weibull distributions, courtesy Jeremy Hylton. Guido van Rossum <guido@python.org> parents: 1618 diff changeset	618
16265 d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	619 ## -------------------- Weibull --------------------
6698 b73eb4e6face Added Pareto and Weibull distributions, courtesy Jeremy Hylton. Guido van Rossum <guido@python.org> parents: 1618 diff changeset	620
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	621 def weibullvariate(self, alpha, beta):
23531 a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	622 """Weibull distribution.
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	623
a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	624 alpha is the scale parameter and beta is the shape parameter.
23536 0a4c92559a0b Whitespace normalized. Raymond Hettinger <python@rcn.com> parents: 23531 diff changeset	625
23531 a98e93eafef7 Deprecated Random.cunifvariate clearing bug 506647. Also, added docstrings. Raymond Hettinger <python@rcn.com> parents: 23521 diff changeset	626 """
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	627 # Jain, pg. 499; bug fix courtesy Bill Arms
11200 bca2d14f3e36 Add Tim Peters' shuffle() algorithm. Guido van Rossum <guido@python.org> parents: 8802 diff changeset	628
27085 90350b5d3397 Correct long standing bugs in the methods for random distributions. Raymond Hettinger <python@rcn.com> parents: 27080 diff changeset	629 u = 1.0 - self.random()
64567 b1865ca7b65c * Remove dependency on binascii.hexlify by using int.from_bytes(). Raymond Hettinger <python@rcn.com> parents: 64553 diff changeset	630 return alpha * (-_log(u)) ** (1.0/beta)
11200 bca2d14f3e36 Add Tim Peters' shuffle() algorithm. Guido van Rossum <guido@python.org> parents: 8802 diff changeset	631
33481 eacdc29606d8 SF #1027105: HardwareRandom should be renamed OSRandom Raymond Hettinger <python@rcn.com> parents: 33409 diff changeset	632 ## --------------- Operating System Random Source ------------------
33329 97fca735c8da Teach the random module about os.urandom(). Raymond Hettinger <python@rcn.com> parents: 32287 diff changeset	633
33481 eacdc29606d8 SF #1027105: HardwareRandom should be renamed OSRandom Raymond Hettinger <python@rcn.com> parents: 33409 diff changeset	634 class SystemRandom(Random):
eacdc29606d8 SF #1027105: HardwareRandom should be renamed OSRandom Raymond Hettinger <python@rcn.com> parents: 33409 diff changeset	635 """Alternate random number generator using sources provided
eacdc29606d8 SF #1027105: HardwareRandom should be renamed OSRandom Raymond Hettinger <python@rcn.com> parents: 33409 diff changeset	636 by the operating system (such as /dev/urandom on Unix or
eacdc29606d8 SF #1027105: HardwareRandom should be renamed OSRandom Raymond Hettinger <python@rcn.com> parents: 33409 diff changeset	637 CryptGenRandom on Windows).
33329 97fca735c8da Teach the random module about os.urandom(). Raymond Hettinger <python@rcn.com> parents: 32287 diff changeset	638
97fca735c8da Teach the random module about os.urandom(). Raymond Hettinger <python@rcn.com> parents: 32287 diff changeset	639 Not available on all systems (see os.urandom() for details).
97fca735c8da Teach the random module about os.urandom(). Raymond Hettinger <python@rcn.com> parents: 32287 diff changeset	640 """
97fca735c8da Teach the random module about os.urandom(). Raymond Hettinger <python@rcn.com> parents: 32287 diff changeset	641
97fca735c8da Teach the random module about os.urandom(). Raymond Hettinger <python@rcn.com> parents: 32287 diff changeset	642 def random(self):
97fca735c8da Teach the random module about os.urandom(). Raymond Hettinger <python@rcn.com> parents: 32287 diff changeset	643 """Get the next random number in the range [0.0, 1.0)."""
64567 b1865ca7b65c * Remove dependency on binascii.hexlify by using int.from_bytes(). Raymond Hettinger <python@rcn.com> parents: 64553 diff changeset	644 return (int.from_bytes(_urandom(7), 'big') >> 3) * RECIP_BPF
33329 97fca735c8da Teach the random module about os.urandom(). Raymond Hettinger <python@rcn.com> parents: 32287 diff changeset	645
97fca735c8da Teach the random module about os.urandom(). Raymond Hettinger <python@rcn.com> parents: 32287 diff changeset	646 def getrandbits(self, k):
85418 4d62a62ba44d Issue #18783: Removed existing mentions of Python long type in docstrings, Serhiy Storchaka <storchaka@gmail.com> parents: 83288 diff changeset	647 """getrandbits(k) -> x. Generates an int with k random bits."""
33329 97fca735c8da Teach the random module about os.urandom(). Raymond Hettinger <python@rcn.com> parents: 32287 diff changeset	648 if k <= 0:
97fca735c8da Teach the random module about os.urandom(). Raymond Hettinger <python@rcn.com> parents: 32287 diff changeset	649 raise ValueError('number of bits must be greater than zero')
97fca735c8da Teach the random module about os.urandom(). Raymond Hettinger <python@rcn.com> parents: 32287 diff changeset	650 if k != int(k):
97fca735c8da Teach the random module about os.urandom(). Raymond Hettinger <python@rcn.com> parents: 32287 diff changeset	651 raise TypeError('number of bits should be an integer')
64569 8627c3ec9711 Improve variable name (don't shadow a builtin). Raymond Hettinger <python@rcn.com> parents: 64568 diff changeset	652 numbytes = (k + 7) // 8 # bits / 8 and rounded up
8627c3ec9711 Improve variable name (don't shadow a builtin). Raymond Hettinger <python@rcn.com> parents: 64568 diff changeset	653 x = int.from_bytes(_urandom(numbytes), 'big')
8627c3ec9711 Improve variable name (don't shadow a builtin). Raymond Hettinger <python@rcn.com> parents: 64568 diff changeset	654 return x >> (numbytes * 8 - k) # trim excess bits
33329 97fca735c8da Teach the random module about os.urandom(). Raymond Hettinger <python@rcn.com> parents: 32287 diff changeset	655
44662 c25760c21397 Remove defunct parts of the random module Raymond Hettinger <python@rcn.com> parents: 44129 diff changeset	656 def seed(self, args, *kwds):
33481 eacdc29606d8 SF #1027105: HardwareRandom should be renamed OSRandom Raymond Hettinger <python@rcn.com> parents: 33409 diff changeset	657 "Stub method. Not used for a system random number generator."
33329 97fca735c8da Teach the random module about os.urandom(). Raymond Hettinger <python@rcn.com> parents: 32287 diff changeset	658 return None
97fca735c8da Teach the random module about os.urandom(). Raymond Hettinger <python@rcn.com> parents: 32287 diff changeset	659
97fca735c8da Teach the random module about os.urandom(). Raymond Hettinger <python@rcn.com> parents: 32287 diff changeset	660 def _notimplemented(self, args, *kwds):
33481 eacdc29606d8 SF #1027105: HardwareRandom should be renamed OSRandom Raymond Hettinger <python@rcn.com> parents: 33409 diff changeset	661 "Method should not be called for a system random number generator."
eacdc29606d8 SF #1027105: HardwareRandom should be renamed OSRandom Raymond Hettinger <python@rcn.com> parents: 33409 diff changeset	662 raise NotImplementedError('System entropy source does not have state.')
33329 97fca735c8da Teach the random module about os.urandom(). Raymond Hettinger <python@rcn.com> parents: 32287 diff changeset	663 getstate = setstate = _notimplemented
97fca735c8da Teach the random module about os.urandom(). Raymond Hettinger <python@rcn.com> parents: 32287 diff changeset	664
16265 d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	665 ## -------------------- test program --------------------
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	666
30243 53a322c6de52 Eliminate unnecessary eval() in tests Raymond Hettinger <python@rcn.com> parents: 30114 diff changeset	667 def _test_generator(n, func, args):
15871 62aeefa01fdd Whitespace normalization. Tim Peters <tim.peters@gmail.com> parents: 14617 diff changeset	668 import time
40775 4cdf21a0dbbc Fix most trivially-findable print statements. Guido van Rossum <guido@python.org> parents: 40737 diff changeset	669 print(n, 'times', func.__name__)
29250 34609fa35b11 'sum' is no longer a good variable name. Use 'total' instead. Raymond Hettinger <python@rcn.com> parents: 27279 diff changeset	670 total = 0.0
15871 62aeefa01fdd Whitespace normalization. Tim Peters <tim.peters@gmail.com> parents: 14617 diff changeset	671 sqsum = 0.0
62aeefa01fdd Whitespace normalization. Tim Peters <tim.peters@gmail.com> parents: 14617 diff changeset	672 smallest = 1e10
62aeefa01fdd Whitespace normalization. Tim Peters <tim.peters@gmail.com> parents: 14617 diff changeset	673 largest = -1e10
62aeefa01fdd Whitespace normalization. Tim Peters <tim.peters@gmail.com> parents: 14617 diff changeset	674 t0 = time.time()
62aeefa01fdd Whitespace normalization. Tim Peters <tim.peters@gmail.com> parents: 14617 diff changeset	675 for i in range(n):
30243 53a322c6de52 Eliminate unnecessary eval() in tests Raymond Hettinger <python@rcn.com> parents: 30114 diff changeset	676 x = func(*args)
29250 34609fa35b11 'sum' is no longer a good variable name. Use 'total' instead. Raymond Hettinger <python@rcn.com> parents: 27279 diff changeset	677 total += x
15871 62aeefa01fdd Whitespace normalization. Tim Peters <tim.peters@gmail.com> parents: 14617 diff changeset	678 sqsum = sqsum + x*x
62aeefa01fdd Whitespace normalization. Tim Peters <tim.peters@gmail.com> parents: 14617 diff changeset	679 smallest = min(x, smallest)
62aeefa01fdd Whitespace normalization. Tim Peters <tim.peters@gmail.com> parents: 14617 diff changeset	680 largest = max(x, largest)
62aeefa01fdd Whitespace normalization. Tim Peters <tim.peters@gmail.com> parents: 14617 diff changeset	681 t1 = time.time()
40775 4cdf21a0dbbc Fix most trivially-findable print statements. Guido van Rossum <guido@python.org> parents: 40737 diff changeset	682 print(round(t1-t0, 3), 'sec,', end=' ')
29250 34609fa35b11 'sum' is no longer a good variable name. Use 'total' instead. Raymond Hettinger <python@rcn.com> parents: 27279 diff changeset	683 avg = total/n
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	684 stddev = _sqrt(sqsum/n - avg*avg)
40775 4cdf21a0dbbc Fix most trivially-findable print statements. Guido van Rossum <guido@python.org> parents: 40737 diff changeset	685 print('avg %g, stddev %g, min %g, max %g' % \
4cdf21a0dbbc Fix most trivially-findable print statements. Guido van Rossum <guido@python.org> parents: 40737 diff changeset	686 (avg, stddev, smallest, largest))
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	687
26155 8ceb455f5541 SF patch 629637: Add sample(population, k) method to the random module. Raymond Hettinger <python@rcn.com> parents: 24861 diff changeset	688
8ceb455f5541 SF patch 629637: Add sample(population, k) method to the random module. Raymond Hettinger <python@rcn.com> parents: 24861 diff changeset	689 def _test(N=2000):
30243 53a322c6de52 Eliminate unnecessary eval() in tests Raymond Hettinger <python@rcn.com> parents: 30114 diff changeset	690 _test_generator(N, random, ())
53a322c6de52 Eliminate unnecessary eval() in tests Raymond Hettinger <python@rcn.com> parents: 30114 diff changeset	691 _test_generator(N, normalvariate, (0.0, 1.0))
53a322c6de52 Eliminate unnecessary eval() in tests Raymond Hettinger <python@rcn.com> parents: 30114 diff changeset	692 _test_generator(N, lognormvariate, (0.0, 1.0))
53a322c6de52 Eliminate unnecessary eval() in tests Raymond Hettinger <python@rcn.com> parents: 30114 diff changeset	693 _test_generator(N, vonmisesvariate, (0.0, 1.0))
53a322c6de52 Eliminate unnecessary eval() in tests Raymond Hettinger <python@rcn.com> parents: 30114 diff changeset	694 _test_generator(N, gammavariate, (0.01, 1.0))
53a322c6de52 Eliminate unnecessary eval() in tests Raymond Hettinger <python@rcn.com> parents: 30114 diff changeset	695 _test_generator(N, gammavariate, (0.1, 1.0))
53a322c6de52 Eliminate unnecessary eval() in tests Raymond Hettinger <python@rcn.com> parents: 30114 diff changeset	696 _test_generator(N, gammavariate, (0.1, 2.0))
53a322c6de52 Eliminate unnecessary eval() in tests Raymond Hettinger <python@rcn.com> parents: 30114 diff changeset	697 _test_generator(N, gammavariate, (0.5, 1.0))
53a322c6de52 Eliminate unnecessary eval() in tests Raymond Hettinger <python@rcn.com> parents: 30114 diff changeset	698 _test_generator(N, gammavariate, (0.9, 1.0))
53a322c6de52 Eliminate unnecessary eval() in tests Raymond Hettinger <python@rcn.com> parents: 30114 diff changeset	699 _test_generator(N, gammavariate, (1.0, 1.0))
53a322c6de52 Eliminate unnecessary eval() in tests Raymond Hettinger <python@rcn.com> parents: 30114 diff changeset	700 _test_generator(N, gammavariate, (2.0, 1.0))
53a322c6de52 Eliminate unnecessary eval() in tests Raymond Hettinger <python@rcn.com> parents: 30114 diff changeset	701 _test_generator(N, gammavariate, (20.0, 1.0))
53a322c6de52 Eliminate unnecessary eval() in tests Raymond Hettinger <python@rcn.com> parents: 30114 diff changeset	702 _test_generator(N, gammavariate, (200.0, 1.0))
53a322c6de52 Eliminate unnecessary eval() in tests Raymond Hettinger <python@rcn.com> parents: 30114 diff changeset	703 _test_generator(N, gauss, (0.0, 1.0))
53a322c6de52 Eliminate unnecessary eval() in tests Raymond Hettinger <python@rcn.com> parents: 30114 diff changeset	704 _test_generator(N, betavariate, (3.0, 3.0))
46034 0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	705 _test_generator(N, triangular, (0.0, 1.0, 1.0/3.0))
16265 d614b6e9fb4e Cosmetic changes after some sleep; no change in semantics. Tim Peters <tim.peters@gmail.com> parents: 16243 diff changeset	706
16292 0501c2a10315 New comment block to Clarify a subtlety. Tim Peters <tim.peters@gmail.com> parents: 16272 diff changeset	707 # Create one instance, seeded from current time, and export its methods
26829 f64c96922708 SF patch 658251: Install a C implementation of the Mersenne Twister as the Raymond Hettinger <python@rcn.com> parents: 26564 diff changeset	708 # as module-level functions. The functions share state across all uses
f64c96922708 SF patch 658251: Install a C implementation of the Mersenne Twister as the Raymond Hettinger <python@rcn.com> parents: 26564 diff changeset	709 #(both in the user's code and in the Python libraries), but that's fine
f64c96922708 SF patch 658251: Install a C implementation of the Mersenne Twister as the Raymond Hettinger <python@rcn.com> parents: 26564 diff changeset	710 # for most programs and is easier for the casual user than making them
f64c96922708 SF patch 658251: Install a C implementation of the Mersenne Twister as the Raymond Hettinger <python@rcn.com> parents: 26564 diff changeset	711 # instantiate their own Random() instance.
f64c96922708 SF patch 658251: Install a C implementation of the Mersenne Twister as the Raymond Hettinger <python@rcn.com> parents: 26564 diff changeset	712
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	713 _inst = Random()
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	714 seed = _inst.seed
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	715 random = _inst.random
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	716 uniform = _inst.uniform
46034 0a485593ae1c Merged revisions 61724-61725,61731-61735,61737,61739,61741,61743-61744,61753,61761,61765-61767,61769,61773,61776-61778,61780-61783,61788,61793,61796,61807,61813 via svnmerge from Christian Heimes <christian@cheimes.de> parents: 44665 diff changeset	717 triangular = _inst.triangular
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	718 randint = _inst.randint
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	719 choice = _inst.choice
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	720 randrange = _inst.randrange
26155 8ceb455f5541 SF patch 629637: Add sample(population, k) method to the random module. Raymond Hettinger <python@rcn.com> parents: 24861 diff changeset	721 sample = _inst.sample
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	722 shuffle = _inst.shuffle
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	723 normalvariate = _inst.normalvariate
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	724 lognormvariate = _inst.lognormvariate
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	725 expovariate = _inst.expovariate
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	726 vonmisesvariate = _inst.vonmisesvariate
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	727 gammavariate = _inst.gammavariate
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	728 gauss = _inst.gauss
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	729 betavariate = _inst.betavariate
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	730 paretovariate = _inst.paretovariate
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	731 weibullvariate = _inst.weibullvariate
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	732 getstate = _inst.getstate
3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	733 setstate = _inst.setstate
30649 8841d34a2c37 SF bug #812202: randint is always even Raymond Hettinger <python@rcn.com> parents: 30346 diff changeset	734 getrandbits = _inst.getrandbits
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	735
1575 45728bfecb76 Random variable generators Guido van Rossum <guido@python.org> parents: diff changeset	736 if __name__ == '__main__':
16242 3c5f09422b69 Reworked random.py so that it no longer depends on, and offers all the Tim Peters <tim.peters@gmail.com> parents: 15871 diff changeset	737 _test()

Mercurial > cpython-lru_cache-weakref

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