[Python] python-constraint packages

2020. 9. 15. 01:10분석 Python/구현 및 자료

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python-constraint 패키지에서 제공하는 모듈을 소개

이 모듈 여러개를 적절하게 결합하면 제한 조건을 설정할 수 있을 것 같다.

Type AllDifferentConstraint

Constraint enforcing that values of all given variables are different

problem = Problem()
problem.addVariables(["a", "b"], [1, 2])
problem.getSolutions()

# [{'a': 2, 'b': 2}, {'a': 2, 'b': 1}, {'a': 1, 'b': 2}, {'a': 1, 'b': 1}]

problem.addConstraint(AllDifferentConstraint())
problem.getSolutions()
# [{'a': 2, 'b': 1}, {'a': 1, 'b': 2}]

 

Type AllEqualConstraint

Constraint enforcing that values of all given variables are equal

problem = Problem()
problem.addVariables(["a", "b"], [1, 2])
problem.getSolutions()

# [{'a': 2, 'b': 2}, {'a': 2, 'b': 1}, {'a': 1, 'b': 2}, {'a': 1, 'b': 1}]

problem.addConstraint(AllEqualConstraint())
problem.getSolutions()

# [{'a': 2, 'b': 2}, {'a': 1, 'b': 1}]

Type BacktrackingSolver

Problem solver with backtracking capabilities

problem = Problem(BacktrackingSolver())
problem.addVariables(["a", "b"], [1, 2, 3])
problem.addConstraint(lambda a, b: b > a, ["a", "b"])
solution = problem.getSolution()
solution

# {'a': 2, 'b': 3}

solutions = problem.getSolutions()
solutions

# [{'a': 2, 'b': 3}, {'a': 1, 'b': 2}, {'a': 1, 'b': 3}]

Type ExactSumConstraint

Constraint enforcing that values of given variables sum exactly to a given amount

problem = Problem()
problem.addVariables(["a", "b"], [1, 2])
problem.addConstraint(ExactSumConstraint(3))
problem.getSolutions()

# [{'a': 2, 'b': 1}, {'a': 1, 'b': 2}]

 

Type FunctionConstraint

Constraint which wraps a function defining the constraint logic

problem = Problem()
problem.addVariables(["a", "b"], [1, 2])
def func(a, b):
    return b > a
problem.addConstraint(func, ["a", "b"])
problem.getSolution()

# {'a': 1, 'b': 2}
problem = Problem()
problem.addVariables(["a", "b"], [1, 2])
def func(a, b):
    return b > a
problem.addConstraint(FunctionConstraint(func), ["a", "b"])
problem.getSolution()

# {'a': 1, 'b': 2}

Type InSetConstraint

Constraint enforcing that values of given variables are present in the given set

 

problem = Problem()
problem.addVariables(["a", "b"], [1, 2])
problem.addConstraint(InSetConstraint([1]))
problem.getSolutions()

# [{'a': 1, 'b': 1}]

Type MaxSumConstraint

Constraint enforcing that values of given variables sum up to a given amount

 

problem = Problem()
problem.addVariables(["a", "b"], [1, 2])
problem.addConstraint(MaxSumConstraint(3))
problem.getSolutions()

# [{'a': 2, 'b': 1}, {'a': 1, 'b': 2}, {'a': 1, 'b': 1}]

Type MinConflictsSolver

Problem solver based on the minimum conflicts theory

problem = Problem(MinConflictsSolver())
problem.addVariables(["a", "b"], [1, 2, 3])
problem.addConstraint(lambda a, b: b > a, ["a", "b"])
solution = problem.getSolution()
solution

# {'a': 1, 'b': 2}

Type MinSumConstraint

Constraint enforcing that values of given variables sum at least to a given amount

 

problem = Problem()
problem.addVariables(["a", "b"], [1, 2])
problem.addConstraint(MinSumConstraint(3))
solutionS = problem.getSolutions()
solutionS

# [{'a': 2, 'b': 2}, {'a': 2, 'b': 1}, {'a': 1, 'b': 2}]

Type NotInSetConstraint

Constraint enforcing that values of given variables are not present in the given set

problem = Problem()
problem.addVariables(["a", "b"], [1, 2])
problem.addConstraint(NotInSetConstraint([1]))
problem.getSolutions()

# [{'a': 2, 'b': 2}]

 

Type RecursiveBacktrackingSolver

Recursive problem solver with backtracking capabilities

problem = Problem(RecursiveBacktrackingSolver())
problem.addVariables(["a", "b"], [1, 2, 3])
problem.addConstraint(lambda a, b: b > a, ["a", "b"])
problem.getSolutions()

# [{'a': 1, 'b': 2}, {'a': 1, 'b': 3}, {'a': 2, 'b': 3}]

Type SomeInSetConstraint

Constraint enforcing that at least some of the values of given variables must be present in a given set

problem = Problem()
problem.addVariables(["a", "b"], [1, 2])
problem.addConstraint(SomeInSetConstraint([1]))
problem.getSolutions()

Type SomeNotInSetConstraint

Constraint enforcing that at least some of the values of given variables must not be present in a given set

 

problem = Problem()
problem.addVariables(["a", "b"], [1, 2])
problem.addConstraint(SomeNotInSetConstraint([1]))
problem.getSolutions()

# [{'a': 2, 'b': 2}, {'a': 2, 'b': 1}, {'a': 1, 'b': 2}]

 

 

 

 

 

 

labix.org/doc/constraint/

 

API Documentation

 

labix.org

 

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