Python Forum

Hi,

Following this tutorial: https://bitesofcode.blogspot.co.uk/2011/...3633820729

Once this code it run, the window opens, but there is an error message and the application can't be closed properly i.e. the only way to get out of it is to quit terminal.
The following code is exactly the only difference is the shebang, as I use python3 so use that shebang. I have been working with Qt4 now for a couple of weeks and have not come across this problem before, but I am only just now learning about making sure that only one instance of QApplication is running etc. So there must be something in the code that is causing the problem. Unfortunately I have not found any info on what a display argument is. Any help would be much appreciated.

#!/usr/bin/python3 

""" Main entry point to the nexsys application. """

# define authorship information
__authors__     = ['Eric Hulser']
__author__      = ','.join(__authors__)
__credits__     = []
__copyright__   = 'Copyright (c) 2011'
__license__     = 'GPL'

# maintanence information
__maintainer__  = 'Eric Hulser'
__email__       = '[email protected]'

from PyQt4 import QtGui

def main(argv = None):
   """
   Creates the main window for the nexsys application and begins the \
   QApplication if necessary.
   
   :param      argv | [, ..] || None
   
   :return      error code
   """
   app = None
   
   # create the application if necessary
   if ( not QtGui.QApplication.instance() ):
       app = QtGui.QApplication(argv)
       app.setStyle('plastique')
   
   # create the main window
   QtGui.QMessageBox.information(None, 'Stub', 'Create the Main Window!')
   
   # run the application if necessary
   if ( app ):
       return app.exec_()
   
   # no errors since we're not running our own event loop
   return 0

if ( __name__ == '__main__' ):
   import sys
   sys.exit(main(sys.argv))