python - Writing Another Text File based on Saved File from Tkinter -

i prompt user save file, , want automatically save file along it. example, let's user saves text file under program called "foo.txt", want automatically make text file called "lengthfoo.txt". word "length" before "foo", , ".txt" after "foo". example: when user saves "helloworld.txt", want program automatically save file called "lengthhelloworld.txt"

from ast import literal_eval tkinter import * tkfiledialog import *  def loadfile():     try:         save_file = askopenfile(mode='r', defaultextension=".zw")         lengths_file = open("length%s.zw" % "origsavefilename", "r")         save_file f:             line in f:                 rectlist.extend(literal_eval(line.strip()))         save_file.close()         lengths_file.close()         print "file loaded"  def savefile():     try:         save_file = asksaveasfile(mode='w', defaultextension=".zw")         if save_file not none:             # write file disk             lengths_file = open("length%s.zw" % "origsavefilename", "w")             save_file.close()             print "file saved successfully." 

don't use asksaveasfile, use asksaveasfilename, returns chosen file name instead of opened file.

you can create file name length using like

import os  save_filename = asksaveasfilename() save_filename_split = os.path.split(save_filename) save_filename_length = os.path.join(save_filename_split[0],                                      'length'+save_filename_split[-1]) 

then have 2 file names can open , write stuff to.