dynamic call of functions and generator function (python)

dynamic call of functions and generator function (python)

The following code only prints "good". Why the generator function is not
executed? I noticed with pdb that after executing 'handlers1' the script
reaches the line with f1's definition but then does not get inside the
function. Conversely, it's returned 'GeneratorExit: None'.
class foo:
def f0(self, s):
print s
def f1(self, s):
print "not " + s
yield 1
def run(self):
handlers={0 : self.f0, 1 : self.f1}
handlers[0]('good')
handlers[1]('good')
bar = foo()
bar.run()
Why this happens? Is it possible to call generator functions in a similar
dynamic way?