* Remove dependency on binascii.hexlify by using int.from_bytes().

* Use the new super() with no arguments.
* Replace pow() call with the ** operator.
* Increase urandom seeding from 16 bytes to 32 bytes.
* Clean-up docstring.
This commit is contained in:
Raymond Hettinger 2010-09-08 18:48:21 +00:00
parent f69af1e959
commit 183cd1fae3
1 changed files with 9 additions and 10 deletions

View File

@ -42,7 +42,6 @@ from types import MethodType as _MethodType, BuiltinMethodType as _BuiltinMethod
from math import log as _log, exp as _exp, pi as _pi, e as _e, ceil as _ceil
from math import sqrt as _sqrt, acos as _acos, cos as _cos, sin as _sin
from os import urandom as _urandom
from binascii import hexlify as _hexlify
import collections as _collections
__all__ = ["Random","seed","random","uniform","randint","choice","sample",
@ -97,16 +96,16 @@ class Random(_random.Random):
None or no argument seeds from current time or from an operating
system specific randomness source if available.
For version 2 (the default), all of the bits are used if a is a str,
bytes, or bytearray. For version 1, the hash() of a is used instead.
For version 2 (the default), all of the bits are used if *a *is a str,
bytes, or bytearray. For version 1, the hash() of *a* is used instead.
If a is an int, all bits are used.
If *a* is an int, all bits are used.
"""
if a is None:
try:
a = int(_hexlify(_urandom(16)), 16)
a = int.from_bytes(_urandom(32), 'big')
except NotImplementedError:
import time
a = int(time.time() * 256) # use fractional seconds
@ -114,7 +113,7 @@ class Random(_random.Random):
if version == 2 and isinstance(a, (str, bytes, bytearray)):
if isinstance(a, str):
a = a.encode("utf8")
a = int(_hexlify(a), 16)
a = int.from_bytes(a, 'big')
super().seed(a)
self.gauss_next = None
@ -139,7 +138,7 @@ class Random(_random.Random):
internalstate = tuple(x % (2**32) for x in internalstate)
except ValueError as e:
raise TypeError from e
super(Random, self).setstate(internalstate)
super().setstate(internalstate)
else:
raise ValueError("state with version %s passed to "
"Random.setstate() of version %s" %
@ -613,7 +612,7 @@ class Random(_random.Random):
# Jain, pg. 499; bug fix courtesy Bill Arms
u = 1.0 - self.random()
return alpha * pow(-_log(u), 1.0/beta)
return alpha * (-_log(u)) ** (1.0/beta)
## --------------- Operating System Random Source ------------------
@ -627,7 +626,7 @@ class SystemRandom(Random):
def random(self):
"""Get the next random number in the range [0.0, 1.0)."""
return (int(_hexlify(_urandom(7)), 16) >> 3) * RECIP_BPF
return (int.from_bytes(_urandom(7), 'big') >> 3) * RECIP_BPF
def getrandbits(self, k):
"""getrandbits(k) -> x. Generates a long int with k random bits."""
@ -636,7 +635,7 @@ class SystemRandom(Random):
if k != int(k):
raise TypeError('number of bits should be an integer')
bytes = (k + 7) // 8 # bits / 8 and rounded up
x = int(_hexlify(_urandom(bytes)), 16)
x = int.from_bytes(_urandom(bytes), 'big')
return x >> (bytes * 8 - k) # trim excess bits
def seed(self, *args, **kwds):