Minor clean-up of function parameters in random().

This commit is contained in:
Raymond Hettinger 2013-10-05 21:48:21 -07:00
parent 81a93159d7
commit 8fe47c3991
1 changed files with 17 additions and 11 deletions

View File

@ -162,18 +162,17 @@ class Random(_random.Random):
## -------------------- integer methods -------------------
def randrange(self, start, stop=None, step=1, int=int):
def randrange(self, start, stop=None, step=1, _int=int):
"""Choose a random item from range(start, stop[, step]).
This fixes the problem with randint() which includes the
endpoint; in Python this is usually not what you want.
Do not supply the 'int' argument.
"""
# This code is a bit messy to make it fast for the
# common case while still doing adequate error checking.
istart = int(start)
istart = _int(start)
if istart != start:
raise ValueError("non-integer arg 1 for randrange()")
if stop is None:
@ -182,7 +181,7 @@ class Random(_random.Random):
raise ValueError("empty range for randrange()")
# stop argument supplied.
istop = int(stop)
istop = _int(stop)
if istop != stop:
raise ValueError("non-integer stop for randrange()")
width = istop - istart
@ -192,7 +191,7 @@ class Random(_random.Random):
raise ValueError("empty range for randrange() (%d,%d, %d)" % (istart, istop, width))
# Non-unit step argument supplied.
istep = int(step)
istep = _int(step)
if istep != step:
raise ValueError("non-integer step for randrange()")
if istep > 0:
@ -251,7 +250,7 @@ class Random(_random.Random):
raise IndexError('Cannot choose from an empty sequence')
return seq[i]
def shuffle(self, x, random=None, int=int):
def shuffle(self, x, random=None):
"""x, random=random.random -> shuffle list x in place; return None.
Optional arg random is a 0-argument function returning a random
@ -260,11 +259,18 @@ class Random(_random.Random):
Do not supply the 'int' argument.
"""
randbelow = self._randbelow
for i in reversed(range(1, len(x))):
# pick an element in x[:i+1] with which to exchange x[i]
j = randbelow(i+1) if random is None else int(random() * (i+1))
x[i], x[j] = x[j], x[i]
if random is None:
randbelow = self._randbelow
for i in reversed(range(1, len(x))):
# pick an element in x[:i+1] with which to exchange x[i]
j = randbelow(i+1)
x[i], x[j] = x[j], x[i]
else:
_int = int
for i in reversed(range(1, len(x))):
# pick an element in x[:i+1] with which to exchange x[i]
j = _int(random() * (i+1))
x[i], x[j] = x[j], x[i]
def sample(self, population, k):
"""Chooses k unique random elements from a population sequence or set.