Problems loading pygtk on Ubuntu 11.04
Question: I'm trying to use pygtk in Python but when I try running my code I get this
error:

    
    
    Traceback (most recent call last):
      File "application.py", line 3, in <module>
        pygtk.require(2.0)
      File "/usr/lib/python2.7/dist-packages/pygtk.py", line 85, in require
        "required version '%s' not found on system" % version
    AssertionError: required version '2.0' not found on system
    

Here is the code I'm trying to run (it's basically the Hello World example
from the pygtk website):

    
    
    #!/usr/bin/env python
    import pygtk
    pygtk.require(2.0)
    import gtk
    
    class Application():
      def hello(self, widget, data=None):
        print 'Hello World'
    
      def delete_event(self, widget, event, data=None):
        print 'delete even occurred'
        return False
    
      def destroy(self, widget, data=None):
        gtk.main_quit()
    
      def __init__(self):
        self.window = gtk.Window(gtk.WINDOW_TOPLEVEL)
        self.window.connect('delete_event', self.delete_event)
        self.quitButton = Button(self, text='Quit', command=self.quit)
        self.quitButton.grid()
        self.window.set_border_width(10)
        self.button = gtk.Button('Hello World')
        self.button.connect('clicked', self.hello, None)
        self.button.connect_object('clicked', gtk.Widget.destroy, self.window)
        self.window.add(self.button)
        self.button.show()
    
      def main(self):
        gtk.main()
    
    def main():
      app = Application()
      app.main()
    
    if __name__ == '__main__':
      main()
    

Also, when I try running `pygtk-demo` everything works ok, even though it is
importing the library the same way that I am. Also it outputs `PyGTK Demo
(gtk: v2.24.4, pygtk: v2.22.0)` so you can see that I have a version that is
>2.0.


Answer: The 3rd line in your file should read:

    
    
    pygtk.require('2.0')
    

Because `2.0` is a string in this case, not a float.

