decorator_sample.py

# Please note, this is a simplified example that ignores
# the function parameters. In practice, you should use
# the decorator module or another method of maintaining
# method signatures.
def mydecorator(f):
    print "It would not be safe to use the session here."
    def decorated():
        print "It would be safe to use the session here."
        return f()
    print "Once more, it would not be safe to use the session here."
    return decorated

class MyController(BaseController):
    @mydecorator
    def do_something(self):
        return "Hello World"

# The reason it's safe to use the session INSIDE the 'decorated'
# function is because that function wraps around the do_something
# method. The two lines outside of decorated are executed while
# Python is parsing the MyController class. The line INSIDE is
# executed during the request. You can only use the session
# during a request.