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authorGuido van Rossum <guido@python.org>2000-02-04 15:28:42 (GMT)
committerGuido van Rossum <guido@python.org>2000-02-04 15:28:42 (GMT)
commite7b146fb3bdca62a0d5ecc06dbf3348e5a4fe757 (patch)
treee1dda862f680cf4a1169220af2ecbca3322caf4d /Lib/whrandom.py
parent54f22ed30bab2e64909ba2d79205cb4b87c69db2 (diff)
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The third and final doc-string sweep by Ka-Ping Yee.
The attached patches update the standard library so that all modules have docstrings beginning with one-line summaries. A new docstring was added to formatter. The docstring for os.py was updated to mention nt, os2, ce in addition to posix, dos, mac.
Diffstat (limited to 'Lib/whrandom.py')
-rw-r--r--Lib/whrandom.py125
1 files changed, 58 insertions, 67 deletions
diff --git a/Lib/whrandom.py b/Lib/whrandom.py
index 7f8fc60..fd9b1a9 100644
--- a/Lib/whrandom.py
+++ b/Lib/whrandom.py
@@ -1,54 +1,52 @@
-# WICHMANN-HILL RANDOM NUMBER GENERATOR
-#
-# Wichmann, B. A. & Hill, I. D. (1982)
-# Algorithm AS 183:
-# An efficient and portable pseudo-random number generator
-# Applied Statistics 31 (1982) 188-190
-#
-# see also:
-# Correction to Algorithm AS 183
-# Applied Statistics 33 (1984) 123
-#
-# McLeod, A. I. (1985)
-# A remark on Algorithm AS 183
-# Applied Statistics 34 (1985),198-200
-#
-#
-# USE:
-# whrandom.random() yields double precision random numbers
-# uniformly distributed between 0 and 1.
-#
-# whrandom.seed(x, y, z) must be called before whrandom.random()
-# to seed the generator
-#
-# There is also an interface to create multiple independent
-# random generators, and to choose from other ranges.
-
-
-# Translated by Guido van Rossum from C source provided by
-# Adrian Baddeley.
-
-
-# Multi-threading note: the random number generator used here is not
-# thread-safe; it is possible that nearly simultaneous calls in
-# different theads return the same random value. To avoid this, you
-# have to use a lock around all calls. (I didn't want to slow this
-# down in the serial case by using a lock here.)
+"""Wichman-Hill random number generator.
+Wichmann, B. A. & Hill, I. D. (1982)
+Algorithm AS 183:
+An efficient and portable pseudo-random number generator
+Applied Statistics 31 (1982) 188-190
+
+see also:
+ Correction to Algorithm AS 183
+ Applied Statistics 33 (1984) 123
+
+ McLeod, A. I. (1985)
+ A remark on Algorithm AS 183
+ Applied Statistics 34 (1985),198-200
+
+
+USE:
+whrandom.random() yields double precision random numbers
+ uniformly distributed between 0 and 1.
+
+whrandom.seed(x, y, z) must be called before whrandom.random()
+ to seed the generator
+
+There is also an interface to create multiple independent
+random generators, and to choose from other ranges.
+
+
+Translated by Guido van Rossum from C source provided by
+Adrian Baddeley.
+
+
+
+Multi-threading note: the random number generator used here is not
+thread-safe; it is possible that nearly simultaneous calls in
+different theads return the same random value. To avoid this, you
+have to use a lock around all calls. (I didn't want to slow this
+down in the serial case by using a lock here.)
+"""
class whrandom:
- #
- # Initialize an instance.
- # Without arguments, initialize from current time.
- # With arguments (x, y, z), initialize from them.
- #
def __init__(self, x = 0, y = 0, z = 0):
+ """Initialize an instance.
+ Without arguments, initialize from current time.
+ With arguments (x, y, z), initialize from them."""
self.seed(x, y, z)
- #
- # Set the seed from (x, y, z).
- # These must be integers in the range [0, 256).
- #
+
def seed(self, x = 0, y = 0, z = 0):
+ """Set the seed from (x, y, z).
+ These must be integers in the range [0, 256)."""
if not type(x) == type(y) == type(z) == type(0):
raise TypeError, 'seeds must be integers'
if not (0 <= x < 256 and 0 <= y < 256 and 0 <= z < 256):
@@ -63,10 +61,9 @@ class whrandom:
t, z = divmod(t, 256)
# Zero is a poor seed, so substitute 1
self._seed = (x or 1, y or 1, z or 1)
- #
- # Get the next random number in the range [0.0, 1.0).
- #
+
def random(self):
+ """Get the next random number in the range [0.0, 1.0)."""
# This part is thread-unsafe:
# BEGIN CRITICAL SECTION
x, y, z = self._seed
@@ -79,30 +76,25 @@ class whrandom:
# END CRITICAL SECTION
#
return (x/30269.0 + y/30307.0 + z/30323.0) % 1.0
- #
- # Get a random number in the range [a, b).
- #
+
def uniform(self, a, b):
+ """Get a random number in the range [a, b)."""
return a + (b-a) * self.random()
- #
- # Get a random integer in the range [a, b] including both end points.
- # (Deprecated; use randrange below.)
- #
+
def randint(self, a, b):
+ """Get a random integer in the range [a, b] including both end points.
+ (Deprecated; use randrange below.)"""
return self.randrange(a, b+1)
- #
- # Choose a random element from a non-empty sequence.
- #
+
def choice(self, seq):
+ """Choose a random element from a non-empty sequence."""
return seq[int(self.random() * len(seq))]
- #
- # Choose a random item from range([start,] step[, stop]).
- # This fixes the problem with randint() which includes the
- # endpoint; in Python this is usually not what you want.
- #
- def randrange(self, start, stop=None, step=1,
- # Do not supply the following arguments
- int=int, default=None):
+
+ def randrange(self, start, stop=None, step=1, int=int, default=None):
+ """Choose a random item from range([start,] step[, stop]).
+ This fixes the problem with randint() which includes the
+ endpoint; in Python this is usually not what you want.
+ Do not supply the 'int' and 'default' arguments."""
# This code is a bit messy to make it fast for the
# common case while still doing adequate error checking
istart = int(start)
@@ -136,7 +128,6 @@ class whrandom:
# Initialize from the current time
-#
_inst = whrandom()
seed = _inst.seed
random = _inst.random