code: def checksum(digits):
      
      weights_for_check_digit = [9, 7, 3, 1, 9, 7, 3, 1, 9, 7]
      check_digit = 0
  
      for i in range(0, 10):
          check_digit += weights_for_check_digit[i] * digits[i]
  
      check_digit %= 10
  
      return check_digit
docs: Calculates and returns a control digit for given list of digits basing on PESEL standard.