python-constraint 1.4.0

简介

Python约束模块为在有限域上提供约束满足问题（CSPs）的求解器，采用简单和纯Python编写。

示例

>>> from constraint import *
>>> problem = Problem()
>>> problem.addVariable("a", [1,2,3])
>>> problem.addVariable("b", [4,5,6])
>>> problem.getSolutions()
[{'a': 3, 'b': 6}, {'a': 3, 'b': 5}, {'a': 3, 'b': 4},
 {'a': 2, 'b': 6}, {'a': 2, 'b': 5}, {'a': 2, 'b': 4},
 {'a': 1, 'b': 6}, {'a': 1, 'b': 5}, {'a': 1, 'b': 4}]

>>> problem.addConstraint(lambda a, b: a*2 == b,
                          ("a", "b"))
>>> problem.getSolutions()
[{'a': 3, 'b': 6}, {'a': 2, 'b': 4}]

>>> problem = Problem()
>>> problem.addVariables(["a", "b"], [1, 2, 3])
>>> problem.addConstraint(AllDifferentConstraint())
>>> problem.getSolutions()
[{'a': 3, 'b': 2}, {'a': 3, 'b': 1}, {'a': 2, 'b': 3},
 {'a': 2, 'b': 1}, {'a': 1, 'b': 2}, {'a': 1, 'b': 3}]

>>> problem = Problem()
>>> numpieces = 8
>>> cols = range(numpieces)
>>> rows = range(numpieces)
>>> problem.addVariables(cols, rows)
>>> for col1 in cols:
...     for col2 in cols:
...         if col1 < col2:
...             problem.addConstraint(lambda row1, row2: row1 != row2,
...                                   (col1, col2))
>>> solutions = problem.getSolutions()
>>> solutions
>>> solutions
[{0: 7, 1: 6, 2: 5, 3: 4, 4: 3, 5: 2, 6: 1, 7: 0},
 {0: 7, 1: 6, 2: 5, 3: 4, 4: 3, 5: 2, 6: 0, 7: 1},
 {0: 7, 1: 6, 2: 5, 3: 4, 4: 3, 5: 1, 6: 2, 7: 0},
 {0: 7, 1: 6, 2: 5, 3: 4, 4: 3, 5: 1, 6: 0, 7: 2},
 ...
 {0: 7, 1: 5, 2: 3, 3: 6, 4: 2, 5: 1, 6: 4, 7: 0},
 {0: 7, 1: 5, 2: 3, 3: 6, 4: 1, 5: 2, 6: 0, 7: 4},
 {0: 7, 1: 5, 2: 3, 3: 6, 4: 1, 5: 2, 6: 4, 7: 0},
 {0: 7, 1: 5, 2: 3, 3: 6, 4: 1, 5: 4, 6: 2, 7: 0},
 {0: 7, 1: 5, 2: 3, 3: 6, 4: 1, 5: 4, 6: 0, 7: 2},
 ...]

>>> problem = Problem()
>>> problem.addVariables(range(0, 16), range(1, 16 + 1))
>>> problem.addConstraint(AllDifferentConstraint(), range(0, 16))
>>> problem.addConstraint(ExactSumConstraint(34), [0, 5, 10, 15])
>>> problem.addConstraint(ExactSumConstraint(34), [3, 6, 9, 12])
>>> for row in range(4):
...     problem.addConstraint(ExactSumConstraint(34),
                              [row * 4 + i for i in range(4)])
>>> for col in range(4):
...     problem.addConstraint(ExactSumConstraint(34),
                              [col + 4 * i for i in range(4)])
>>> solutions = problem.getSolutions()

功能

以下是一些可用的求解器：

• 回溯求解器

• 递归回溯求解器

• 最小冲突求解器

当前可用的预定义约束类型

• 函数约束

• 全不同约束

• 全相等约束

• 精确求和约束

• 最大求和约束

• 最小求和约束

• 在集合约束

• 不在集合约束

• 某些在集合约束

• 某些不在集合约束

API 文档

模块文档可在以下地址获取： http://labix.org/doc/constraint/

下载和安装

$ pip install python-constraint

路线图

这个 GitHub 组织和仓库是全球合作项目，旨在维护由 Gustavo Niemeyer 编写的 python-constraint，最初位于 https://labix.org/python-constraint

• 创建一些单元测试 - 已完成

• 启用持续集成 - 已完成

• 移植到 Python 3（同时支持 Python 2） - 已完成

• 遵守 Python 代码风格指南（PEP8） - 已完成

• 通过编写更多单元测试来提高代码覆盖率 - 待办

• 将文档移至 Sphinx 或 MkDocs - https://readthedocs.org/ - 待办

联系

• Gustavo Niemeyer <gustavo@niemeyer.net>

• Sébastien Celles <s.celles@gmail.com>

但最好还是 打开一个 issue。