Python add to a function dynamically

Question

how do i add code to an existing function, either before or after?

for example, i have a class:

 class A(object):
     def test(self):
         print         


        

Answer 1

Copy and paste, enjoy!!!!!

#!/usr/bin/env python 

def say(host, msg): 
   print '%s says %s' % (host.name, msg) 

def funcToMethod(func, clas, method_name=None): 
   setattr(clas, method_name or func.__name__, func) 

class transplant: 
   def __init__(self, method, host, method_name=None): 
      self.host = host 
      self.method = method 
      setattr(host, method_name or method.__name__, self) 

   def __call__(self, *args, **kwargs): 
      nargs = [self.host] 
      nargs.extend(args) 
      return apply(self.method, nargs, kwargs) 

class Patient: 
   def __init__(self, name): 
      self.name = name 

if __name__ == '__main__': 
   jimmy = Patient('Jimmy') 
   transplant(say, jimmy, 'say1') 
   funcToMethod(say, jimmy, 'say2') 

   jimmy.say1('Hello') 
   jimmy.say2(jimmy, 'Good Bye!')