pyqt4 - How to raise traceback of other class in main class in python -

i coding in python , added trace-backs error handling.

for better understanding, lets have 3 classes.

c1 = main class

traceback = other class

my main class import other classes (traceback) , create instances of these class , proceeds coded. error handling imported traceback module in 3 classes , updated code within try: except: working fine desired.

now got idea, keep traceback in main class. other classes imported in main class.

my c1.py looks below

import traceback traceback import c3  class tracebacktest():      def __init__(self):          try:              self.c3_inst = c3(1,0)             self.c3_inst.sub()                       except exception ex:              tracebk = traceback.format_exc()             print 'error raised trace back\n%s' % tracebk  if __name__ == '__main__':      import sys     pyqt4 import qtgui      app = qtgui.qapplication(sys.argv)     win = tracebacktest()     sys.exit(app.exec_())  

my traceback.py looks below

from pyqt4 import qtgui  class c3(qtgui.qmainwindow):      def __init__(self,x,y):          super(c3,self).__init__()          self.a = x         self.b = y          button = qtgui.qpushbutton('test',self)         button.clicked.connect(self.sub)         self.show()       def sub(self):          result = self.a / self.b          print 'result %s' % result 

in c1.py after creating instance called self.c3_inst.sub() immediately, give below trace exception.

error raised trace traceback (most recent call last):   file "d:\pbl_data\development\showtime_python\rnd\traceback_1a.py", line 25, in __init__     self.c3_inst.sub()   file "d:\pbl_data\development\showtime_python\rnd\traceback.py", line 37, in sub     result = self.a / self.b zerodivisionerror: integer division or modulo 0 

but when click button in window. below error, not raised exception in c1.py

traceback (most recent call last):   file "d:\pbl_data\development\showtime_python\rnd\traceback.py", line 37, in sub     result = self.a / self.b zerodivisionerror: integer division or modulo 0 

can 1 tell me actual approach trackback work in pyqt connected widget signals.

by time click button, python long past try..except surrounding self.c3_inst = c3(1,0). if want catch exception in c1.py, you'd need put try..except around app.exec_().