Some tools of IMEI code.

imei.py

#! /usr/bin/env python3

class imei():
    @staticmethod
    def calculus(imei):
        '''
        @brief calculus check digit of imei numbers
        @param imei imei serial numbers
        @retval check digit characters
        '''

        # check format 
        if not imei.isdigit() or 14 != len(imei):
            raise Exception("Invalid imei format!")

        digits = [(1+i%2)*int(d) for i,d in enumerate(imei)]
        '''
        digits = []
        for i,d in enumerate(imei):
            if i % 2 == 1:
                digits.append(2*int(d))
            else:
                digits.append(int(d))
        '''
        #print(digits)

        digits = map(lambda d : sum(divmod(d,10)), digits)
        result = (10 - (sum(digits) % 10))%10

        return result
        
    @staticmethod
    def check(calculus,imei):
        '''
        @brief check imei serial numbers
        @param calculue imei check digit calculus function
        @param imei imei serial numbers 
        @retval bool value
        '''

        # check imei format
        if not imei.isdigit() or 15 != len(imei):
            raise Exception("Invalid imei format!")

        cd = calculus(imei[:-1])

        return int(imei[-1]) == cd

if '__main__' == __name__:
    print(imei.calculus("35145120840121"))
    print(imei.check(imei.calculus,"351451208401216"))