Restricted Combinations

rcombinations.py

# -*- coding: utf-8 -*-
"""
rcombinations.py
~~~~~~~~~~~~~~~~

Implements different a restricted combination function.

This is free and unencumbered software released into the public domain.

Anyone is free to copy, modify, publish, use, compile, sell, or
distribute this software, either in source code form or as a compiled
binary, for any purpose, commercial or non-commercial, and by any
means.

In jurisdictions that recognize copyright laws, the author or authors
of this software dedicate any and all copyright interest in the
software to the public domain. We make this dedication for the benefit
of the public at large and to the detriment of our heirs and
successors. We intend this dedication to be an overt act of
relinquishment in perpetuity of all present and future rights to this
software under copyright law.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

For more information, please refer to <http://unlicense.org/>
"""

__author__ = "Carlos Killpack"
__email__ = "[email protected]"
__license__ = "Unlicense <http://unlicense.org>"


from itertools import chain, izip


def rcombinations(values=None):
    length = len(values)
    for combination in set(chain(fill(values=values, length=length),
                                 drain(values=values, length=length),
                                 hit(values=values, length=length),
                                 miss(values=values, length=length),
                                 alt2(values=values, length=length))):
        yield combination


def fill(values=None):
    length = len(values)
    for index in range(length):
        yield tuple(chain(values[0:index], (None for _ in range(length - index))))
    yield tuple(i for i in values)


def drain(values=None):
    length = len(values)
    for index in reversed(range(length)):
        if length - index == length:
            pass
        else:
            yield tuple(chain((None for _ in range(length - index)), values[-index:]))
    yield tuple(None for _ in range(length))


def alt2(values=None):
    length = len(values)
    combination_set = set()
    for i in range(length):
        for j in range(length - 1):
            combination = [None for _ in range(length)]
            if i == j + 1:
                pass
            else:
                combination[i] = values[i]
                combination[j + 1] = values[j + 1]
                combination_set.update([tuple(combination)])
    for combination in combination_set:
        yield tuple(combination)


def alt3(values=None):
    length = len(values)
    combination_set = set()
    for i in range(length):
        for j in range(length - 1):
            combination = [None for _ in range(length)]
            try:
                combination[j] = values[j]
                combination[j + 1] = values[j + 1]
                combination[j + 2] = values[j + 2]
                combination_set.update([tuple(combination)])
            except IndexError:
                pass
    for combination in combination_set:
        yield tuple(combination)


def cluster(values=None):
    length = len(values)
    def _cluster(size):
        print size
        for i, j in izip(range(length), range(size, length + size)):
            if j > len(values):
                group = list(values[:j - len(values)])
                group.extend(values[i:len(values)])
            else:
                group = values[i:j]
            print group
    for combination in chain(*[_cluster(size + 1) for size in range(length - 1)]):
        yield combination


def hit(values=None):
    length = len(values)
    for index in range(length):
        combination = [None for _ in range(length)]
        combination[index] = values[index]
        yield tuple(combination)


def miss(values=None):
    length = len(values)
    for index in range(length):
        combination = [value for value in values]
        combination[index] = None
        yield tuple(combination)
        

setup.py

# -*- coding: utf-8 -*-

from setuptools import setup

setup(name="rcombinations",
      version="0",
      author="Carlos Killpack",
      author_email="[email protected]",
      license="Public Domain",
      py_modules=("rcombinations", ),
      classifiers=("Topic :: Utilities",
                   "License :: Public Domain", ))

tests.py

# -*- coding: utf-8 -*-

from unittest import TestCase
from itertools import chain

from rcombinations import fill, drain, hit, miss


class TestRCombinations(TestCase):
    def setUp(self):
        self.values = ('a', 'b', 'c', 'd', 'e')
        self.fill_result = [(None, None, None, None, None),
                            ('a', None, None, None, None),
                            ('a', 'b', None, None, None),
                            ('a', 'b', 'c', None, None),
                            ('a', 'b', 'c', 'd', None),
                            ('a', 'b', 'c', 'd', 'e')]
        self.drain_result = [(None, 'b', 'c', 'd', 'e'),
                             (None, None, 'c', 'd', 'e'),
                             (None, None, None, 'd', 'e'),
                             (None, None, None, None, 'e'),
                             (None, None, None, None, None)]
        self.hit_result = [('a', None, None, None, None),
                           (None, 'b', None, None, None),
                           (None, None, 'c', None, None),
                           (None, None, None, 'd', None),
                           (None, None, None, None, 'e')]
        self.miss_result = [(None, 'b', 'c', 'd', 'e'),
                            ('a', None, 'c', 'd', 'e'),
                            ('a', 'b', None, 'd', 'e'),
                            ('a', 'b', 'c', None, 'e'),
                            ('a', 'b', 'c', 'd', None)]
        self.rcombinations_result = list(chain(self.fill_result,
                                               self.drain_result,
                                               self.hit_result,
                                               self.miss_result))

    def test_fill(self):
        self.assertEqual(list(fill(values=self.values)), self.fill_result)

    def test_drain(self):
        self.assertEqual(list(drain(values=self.values)), self.drain_result)

    def test_hit(self):
        self.assertEqual(list(hit(values=self.values)), self.hit_result)

    def test_miss(self):
        self.assertEqual(list(miss(values=self.values)), self.miss_result)