44 lines
722 B
Python
44 lines
722 B
Python
# -*- python -*-
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#
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# $Id: generators.py,v 1.1 2010-02-19 18:41:28 wirawan Exp $
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#
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# Created: 20100218
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# Wirawan Purwanto
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#
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"""
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Various generators
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"""
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def all_combinations(seq):
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"""Generates stream of tuples containing all possible
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combinations of items (where order matters).
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This is useful e.g. for generating all possible indices for a multidimensional
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array.
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Example:
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>>> for i in all_combinations((xrange(4), xrange(3))): print i
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(0, 0)
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(1, 0)
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(2, 0)
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(3, 0)
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(0, 1)
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(1, 1)
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(2, 1)
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(3, 1)
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(0, 2)
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(1, 2)
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(2, 2)
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(3, 2)
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"""
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if len(seq) <= 1:
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for i in seq[0]:
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yield (i,)
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else:
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for s1 in all_combinations(seq[1:]):
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for s0 in seq[0]:
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yield (s0,) + s1
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