new_contents: #!/usr/bin/env python
  # -*- coding: utf-8 -*-
  
  '''
  File: string_to_int.py
  Author: tdoly
  Description: string convert to int without a library, For example, int('111')
  '''
  
  def parseInt(number):
      if len(number) < 1:
          return None
      nums = [(ord(number[-(i+1)])-48) * 10**i for i in range(len(number))]
      return reduce(lambda x, y: x+y, nums)
  
  def test():
      numtest = ['12345', '0', '1', '54321']
      for num in numtest:
          print parseInt(num) == int(num)
  
  if __name__ == '__main__':
      test()
  
subject: add string to int using python