26 lines
649 B
Python
26 lines
649 B
Python
# (c) Copyright 2018 by Coinkite Inc. This file is covered by license found in COPYING-CC.
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#
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# random.py - subset of random module, with no compat, and using crypto-quality rng
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#
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import ngu
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# use this instead of rand%n
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randbelow = ngu.random.uniform
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# for bytes, use ngu.random.byte(len)
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#bytes = ngu.random.bytes
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# In-place list shuffle using Fisher-Yates algo
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#
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# see <https://en.wikipedia.org/wiki/Fisher%E2%80%93Yates_shuffle#Implementation_errors>
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#
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def shuffle(lst):
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# cpython random.py:L286 -- Fisher-Yates
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for i in reversed(range(1, len(lst))):
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j = randbelow(i+1)
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lst[i], lst[j] = lst[j], lst[i]
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# EOF
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