new_contents: # coding: utf-8
  from datetime import date, timedelta
  import os, sys
  import random
  
  def dategenerator(start, end):
      current = start
  
      if start > end:
          print "Please input a valid start-end date."
          yield
  
      while current <= end:
          yield current
          current += timedelta(days=1)
  
  def everyday(date):
      number = random.randint(1, 10)
      datestr = str(date)
      for num in xrange(1, number):
          f = open("cheat.txt", "w")
          writenumber = random.uniform(0, 100)
          f.write(str(writenumber))
          f.close()
          addfile = "git add cheat.txt"
          commit  = "git commit --date=%s -m \"%s modify test\"" % (datestr, datestr)
  
          os.system(addfile)
          os.system(commit)
  
      print datestr + "committed " + str(number) + "time(s)."
  
  
  def main(argv):
      (start_date, end_date) = argv
  
      (start_y, start_m, start_d) = start_date.split('-')
      (end_y, end_m, end_d)       = end_date.split('-')
  
      start = date(int(start_y), int(start_m), int(start_d))
      end   = date(int(end_y), int(end_m), int(end_d))
  
      for day in dategenerator(start, end):
          everyday(day)
  
  if __name__ == '__main__':
      main(sys.argv[1:])
  
subject: add a way of python