Python Forum

# -*- coding: utf-8 -*-
"""
Spyder Editor
This is a temporary script file.
"""
from constraint import *
problem = Problem()
problem.addVariable("1ACROSS",["HOSES","LASER","SAILS","SHEET","STEER"])
problem.addVariable("4ACROSS",["HEEL","HIKE","KEEL","KNOT","LINE"])
problem.addVariable("7ACROSS",["AFT","ALE","EEL","LEE","TIE"])
problem.addVariable("8ACROSS",["HOSES","LASER","SAILS","SHEET","STEER"])
problem.addVariable("2DOWN",  ["HOSES","LASER","SAILS","SHEET","STEER"])
problem.addVariable("3DOWN",  ["HOSES","LASER","SAILS","SHEET","STEER"])
problem.addVariable("5DOWN",["HEEL","HIKE","KEEL","KNOT","LINE"])
problem.addVariable("6DOWN",["AFT","ALE","EEL","LEE","TIE"])
problem.addConstraint(lambda 1ACROSS,2DOWN: 1ACROSS in range((1,1),(1,5)) and 2DOWN in range ((1,3),(5,3)) and 1ACROSS[2]==2DOWN[0])
problem.addConstraint(lambda 3DOWN,1ACROSS: 3DOWN in range((1,5),(5,5)) and 1ACROSS[4]==3DOWN[0])
problem.addConstraint(lambda 4ACROSS,5DOWN: 4ACROSS in range((3,2),(3,5)) and 5DOWN in range ((3,4),(6,4)) and 4ACROSS[1]==2DOWN[2] and 4ACROSS[2]==5DOWN[0] and 4ACROSS[3]==3DOWN[2])
problem.addConstraint(lambda 6DOWN,8ACROSS: 6DOWN in range((4,1),(6,1)) and 8ACROSS in range((5,1),(5,5)) and 6DOWN[1]==8ACROSS[0])
problem.addConstraint(7ACROSS in range((4,3),(4,5)) and 7ACROSS[0]==2DOWN[3] and 7ACROSS[1]==5DOWN[1] and 7ACROSS[2]==3DOWN[3])
problem.addConstraint(8ACROSS in range((5,1),(5,5)) and 8ACROSS[0]==6DOWN[1] and 8ACROSS[2]==2DOWN[4] and 8ACROSS[3]==5DOWN[2] and 8ACROSS[4]==3DOWN[4])
problem.getSolution()

But this code didn't work... any help regarding this . When i run this it gives this output

Error:
line 16
    problem.addConstraint(lambda 1ACROSS,2DOWN: 1ACROSS in range((1,1),(1,5)) and 2DOWN in range ((1,3),(5,3)) and 1ACROSS[2]==2DOWN[0])
                                 ^
SyntaxError: invalid syntax

The documentation for problem.addVariable always shows items in list as numerics, never strings, although I don't see any constraints on doing so:

Output:
addVariable(self, variable, domain)

Add a variable to the problem
Example:

>>> problem = Problem()
>>> problem.addVariable("a", [1, 2])
>>> problem.getSolution() in ({'a': 1}, {'a': 2})
True

    Parameters:
        variable - Object representing a problem variable
                   (type=hashable object) 
        domain - Set of items defining the possible values that the given variable may assume
                   (type=list, tuple, or instance of Domain) 

addVariables(self, variables, domain)

Add one or more variables to the problem
Example:

>>> problem = Problem()
>>> problem.addVariables(["a", "b"], [1, 2, 3])
>>> solutions = problem.getSolutions()
>>> len(solutions)
9

>>> {'a': 3, 'b': 1} in solutions
True

    Parameters:
        variables - Any object containing a sequence of objects represeting problem variables
                   (type=sequence of hashable objects) 
        domain - Set of items defining the possible values that the given variables may assume
                   (type=list, tuple, or instance of Domain) 

If that were an issue, I would expect it to be documented, but don't see it.

I found the example of building a crossword which uses constraints: http://www.cromulentrambling.com/2017/01...ython.html
Please note that the author builds problem thusly:

problem.addVariables(list(range(s*s)), [0,1])

again with a list of numerics for domain.