Handling exception in python tkinter

Question

I have written an application in Python Tkinter. I recently noticed that for one of the operation, it sometimes closes (without giving any error) if that operation failed.

Answer 1

I am not very sure if I have understood you well, but this simple code gives you control over the case in which the directory could not be found:

import os
from Tkinter import *

def copydir():
    src = "D:\\troll"
    dest = "D:\\trollo"

    try:
        os.rename(src, dest)
    except:
        print 'Sorry, I couldnt rename'
        # optionally: raise YourCustomException
        # or use a Tkinter popup to let the user know

master = Tk()

b = Button(master, text="OK", command=copydir)
b.pack()

mainloop()

EDIT: Since you want a general method and Tkinter does not propagate exceptions, you have to program it. There are two ways:

1) Hardcode it into the the functions as I did in the example above (horrible)

2) Use a decorator to add a try-except block.

import os
from Tkinter import *


class ProvideException(object):
    def __init__(self, func):
        self._func = func

    def __call__(self, *args):

        try:
            return self._func(*args)

        except Exception, e:
            print 'Exception was thrown', str(e)
            # Optionally raise your own exceptions, popups etc


@ProvideException
def copydir():
    src = "D:\\troll"
    dest = "D:\\trollo"

    os.rename(src, dest)

master = Tk()

b = Button(master, text="OK", command=copydir)
b.pack()

mainloop()

EDIT: If you want to include the stack

include traceback

and in the except block:

except Exception, e:
    print 'Exception was thrown', str(e)
    print traceback.print_stack()

The solution that A.Rodas has proposed is cleaner and more complete, however, more complicated to understand.