Question

I am using Tkinter to help me build a FTP client, in this client I am trying to get the selected information from a tk listbox. So I have a button that starts the download but what ever the reason is it pops up with the error “

Exception in Tkinter callback
Traceback (most recent call last):
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-tk/Tkinter.py", line 1410, in __call__
    return self.func(*args)
  File "/Volumes/LEGO FLASH/ftp.py", line 23, in Download
    filename = stuff
NameError: global name 'stuff' is not defined" 

Below I have the code for you to look at:

# Import the FTP object from ftplib
from ftplib import FTP
from Tkinter import *
import os

app = Tk()
app.title("FTP")
app.geometry("300x300")

lines = []
#[lines.replace(",", "\n")for lines in lines]
#lines = lines.replace(',','\n')

def handleDownload(block):
    file.write(block)
    print ".",

def append_line(line):
    lines.append(line)

#This is where I am caught-------> 
def Download():

    filename = stuff

    file = open(filename, 'wb')

    ftp.retrbinary('RETR ' + filename, handleDownload)


    ftp.close()

def login():
    try:
        ftp.login(username.get(),password.get())
    except:
        error = Label(app, text = "Invalid USERNAME OR PASSWORD")


    label2 = Label(app, text = "Welcome to Steam Engine").pack()
    username.forget()
    password.forget()
    button.forget()

    app.geometry("800x500")

    download = Button(app, text = "Download!!!!!", command = Download)
    download.pack(side = "left", pady = "5")

    scrollBar.pack(fill = Y, side = "right", padx = "2")

    #ftp.cwd('The_Store')

    stuff = Listbox(app, height = "700", width = "500")
    ftp.retrlines('NLST', append_line)
    for i in lines:
        stuff.insert(END, i)
    stuff.pack(padx = "10", pady = "10")

    stuff.config(yscrollcommand = scrollBar.set)
    scrollBar.config(command = stuff.yview)



ftp = FTP('sciphigames.com')
label = Label(app, text = "Login").pack(pady = "10")

scrollBar = Scrollbar(app)

username = StringVar(None)
username = Entry(app, text = "Username: ")
username.pack(pady = "2")

password = StringVar(None)
password = Entry(app, text = "Password: ")
password.pack(pady = "2")

button = Button(app, text = "Login!", command = login)
button.pack(pady = "10")

app.mainloop()

Any help would be appreciated!

Thanks!

Answer 1

I am not entirely sure what the purpose is with your stuff variable, but the problems you are experiencing probably stem from the way you are using it.

First, you are using it as argument to login (which, by the way should take no arguments). You assign to this variable from the login function, and refer to another variable with the same name in your Download function.

Again, not being sure what I understand what you want to do with the stuff variable, I would try something like

.....

app.geometry("300x300")

stuff = None # <<<<----

lines = []

.....

#This is where I am caught-------> 
def Download():
    global stuff # <<<<----

    filename = stuff

    ......

    ftp.close()

def login():
    global stuff # <<<<----

    ......

    stuff = Listbox(app, height = "700", width = "500")
    ftp.retrlines('NLST', append_line)
    for i in lines:
        stuff.insert(END, i)
    stuff.pack(padx = "10", pady = "10")

    stuff.config(yscrollcommand = scrollBar.set)
    scrollBar.config(command = stuff.yview)


......