Suppose code like this:

class Base: def start(self): pass def stop(self) pass

class A(Base): def start(self): ... do something for A def stop(self) .... do something for A

class B(Base): def start(self):

def stop(self):

a1 = A(); a2 = A() b1 = B(); b2 = B()

all = [a1, b1, b2, a2,.....]

Now I want to call methods start and stop (maybe also others) for each object in the list all. Is there any elegant way for doing this except of writing a bunch of functions like

def start_all(all): for item in all: item.start()

def stop_all(all): .....