#!/usr/bin/env python

# with_example02.py

class Sample:

    def __enter__(self):

        print "go to enter():"

        return self

    def __exit__(self, type, value, trace):

        print "go to exit():"

        print "type:", type

        print "value:", value

        print "trace:", trace

    def do_something(self):

        print "go to do_something():"

        bar = 1/0

        return bar + 10

with Sample() as sample:

    sample.do_something()