71 lines
1.7 KiB
Python
71 lines
1.7 KiB
Python
"""Convenience functions for random operations. Not suitable for security / cryptography operations."""
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import os
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import random
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from pyelliptic.openssl import OpenSSL
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NoneType = type(None)
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def seed():
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"""Initialize random number generator"""
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random.seed()
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def randomBytes(n):
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"""Method randomBytes."""
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try:
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return os.urandom(n)
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except NotImplementedError:
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return OpenSSL.rand(n)
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def randomshuffle(population):
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"""Method randomShuffle.
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shuffle the sequence x in place.
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shuffles the elements in list in place,
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so they are in a random order.
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As Shuffle will alter data in-place,
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so its input must be a mutable sequence.
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In contrast, sample produces a new list
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and its input can be much more varied
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(tuple, string, xrange, bytearray, set, etc)
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"""
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random.shuffle(population)
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def randomsample(population, k):
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"""Method randomSample.
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return a k length list of unique elements
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chosen from the population sequence.
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Used for random sampling
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without replacement, its called
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partial shuffle.
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"""
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return random.sample(population, k)
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def randomrandrange(x, y=None):
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"""Method randomRandrange.
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return a randomly selected element from
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range(start, stop). This is equivalent to
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choice(range(start, stop)),
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but doesnt actually build a range object.
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"""
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if isinstance(y, NoneType):
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return random.randrange(x) # nosec
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else:
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return random.randrange(x, y) # nosec
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def randomchoice(population):
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"""Method randomchoice.
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Return a random element from the non-empty
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sequence seq. If seq is empty, raises
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IndexError.
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"""
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return random.choice(population) # nosec
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