NameError: global name 'gtk' is not defined

Question

I noticed that the 'gtk' is not defined and I couldn't figure out what it meant despite me managing to import PYGTK when it runs. Below is the code:

import sys

importStatus = False

try:
    from gtk import *
    importStatus = True

except ImportError:
    print "PyGTK module does not exist. Can't launch GUI !"
    print "Please download and install GTK and PyGTK."
    importStatus = False

if importStatus:

    class gtkGUI():

        def __init__(self):
            print "gtkGUI imported"

        def startGUI(self):
            print "GUI Started"
            self.window = gtk.Window(gtk.WINDOW_TOPLEVEL)
            return None

Below is the error:

Traceback (most recent call last):
  File "mainGUI.py", line 14, in <module>
    gtk.startGUI()
  File "..../gtkGUI.py", line 25, in startGUI
    gtk.main()
NameError: global name 'gtk' is not defined

How should I solve this error ? Thanks.

Answer 1

You need GTK installed on the system with PyGTK. Usually your import for PyGTK looks something like this:

import pygtk
pygtk.require('2.0')
import gtk

If you look at the PyGTK downloads, you see a reference to installation GTK+. Make sure you do that (I think you're supposed to do it before you install PyGTK, to be fully correct).

Answer 2

gtk isn't defined because you never actually import it as a module. You're using from gtk import * which pulls all the members of the gtk module into the current namespace, rather than importing the module as a whole. So, in line 25, you would have to call Window(WINDOW_TOPLEVEL) and not gtk.Window(gtk.WINDOW_TOPLEVEL).

I would recommend using import gtk rather than from gtk import *.