[Python] cut a big text file into small pieces of certain lines each

file_cut.py

# -*- coding: utf-8 -*-
# Filename:file_cut.py
path = raw_input('please enter the file path:')
savepath = raw_input('please enter the save path:(not include the last \'\\\')')
newname = raw_input('please enter the new name:')
fr = file(path,'r')
flag = True
i = 0 #???
c = 1 #????
while flag:
    line = fr.readline()
    i+=1
    if i < 10000:         #??200000?
        save =savepath +'\\'+ newname + str(c) + ".txt"
        file(save,'a').write(line)
    else:
        i = 0    #?????
        c+=1      #???+1
        continue   #????
    if len(line) == 0:
        flag = False
#    if c == 5:          
#        flag = False
fr.close()
fs.close()