projecteuler---->problem=32----Pandigital products

Problem 32

We shall say that an n-digit number is pandigital if it makes use of all the digits 1 to n exactly once; for example, the 5-digit number, 15234, is 1 through 5 pandigital.

The product 7254 is unusual, as the identity, 39 × 186 = 7254, containing multiplicand, multiplier, and product is 1 through 9 pandigital.

Find the sum of all products whose multiplicand/multiplier/product identity can be written as a 1 through 9 pandigital.

HINT: Some products can be obtained in more than one way so be sure to only include it once in your sum.

def is_pandigital(*args, **kwargs):    #将三个数转化成String并排序    num = sorted(''.join(str(arg) for arg in args))    print num    print "kwargs = ",kwargs    try:        if kwargs['length'] and len(num) != kwargs['length']:            return False    except KeyError:        pass    for i in range(len(num)):        if str(i+1) != str(num[i]):            return False    return Truedef main():    pandigitals = set()    total = 0    for multiplicand in range(1, 5000):        for multiplier in range(1, 100):            product = multiplicand * multiplier            if is_pandigital(multiplicand, multiplier, product, length=9):                pandigitals.add(product)    print sum(pandigitals)if __name__ == "__main__":    main()