Contents

class Luhn(object):
    def __init__(self, string):
        self.string = string.replace(" ", "")

    def addends(self):
        def luhn_transform(n):
            return (2 * n - 9) if (n > 4) else (2 * n)
        old_digits = [int(d) for d in str(self.string)]
        return [(luhn_transform(n) if (i % 2 == 0) else n)
                for i, n in enumerate(old_digits, start=len(old_digits) % 2)]

    def checksum(self):
        return sum(self.addends())

    def is_valid(self):
        if len(self.string) <= 1 or not self.string.isdigit():
            return False
        return self.checksum() % 10 == 0

Version data entries

198 entries across 198 versions & 1 rubygems

Version	Path
trackler-2.2.1.96	tracks/python/exercises/luhn/example.py
trackler-2.2.1.95	tracks/python/exercises/luhn/example.py
trackler-2.2.1.94	tracks/python/exercises/luhn/example.py
trackler-2.2.1.93	tracks/python/exercises/luhn/example.py
trackler-2.2.1.92	tracks/python/exercises/luhn/example.py
trackler-2.2.1.91	tracks/python/exercises/luhn/example.py
trackler-2.2.1.90	tracks/python/exercises/luhn/example.py
trackler-2.2.1.89	tracks/python/exercises/luhn/example.py
trackler-2.2.1.88	tracks/python/exercises/luhn/example.py
trackler-2.2.1.87	tracks/python/exercises/luhn/example.py
trackler-2.2.1.86	tracks/python/exercises/luhn/example.py
trackler-2.2.1.85	tracks/python/exercises/luhn/example.py
trackler-2.2.1.84	tracks/python/exercises/luhn/example.py
trackler-2.2.1.83	tracks/python/exercises/luhn/example.py
trackler-2.2.1.82	tracks/python/exercises/luhn/example.py
trackler-2.2.1.81	tracks/python/exercises/luhn/example.py
trackler-2.2.1.80	tracks/python/exercises/luhn/example.py
trackler-2.2.1.79	tracks/python/exercises/luhn/example.py
trackler-2.2.1.78	tracks/python/exercises/luhn/example.py
trackler-2.2.1.77	tracks/python/exercises/luhn/example.py