Is it possible to replace a Python function/method decorator at runtime?

Question

If I have a function :

@aDecorator
def myfunc1():
  # do something here

if __name__ = "__main__":
  # this will call the function and will use the decorator @aDecorator
  myfunc1() 
  # now I want the @aDecorator to be replaced with the decorator @otherDecorator
  # so that when this code executes, the function no longer goes through
  # @aDecorator, but instead through @otherDecorator. How can I do this?
  myfunc1()

Is it possible to replace a decorator at runtime?

Answer 1

I don't know if there's a way to "replace" a decorator once it has been applied, but I guess that probably there's not, because the function has already been changed.

You might, anyway, apply a decorator at runtime based on some condition:

#!/usr/bin/env python

class PrintCallInfo:
    def __init__(self,f):
        self.f = f
    def __call__(self,*args,**kwargs):
        print "-->",self.f.__name__,args,kwargs
        r = self.f(*args,**kwargs)
        print "<--",self.f.__name__,"returned: ",r
        return r

# the condition to modify the function...
some_condition=True

def my_decorator(f):
    if (some_condition): # modify the function
        return PrintCallInfo(f)
    else: # leave it as it is
        return f

@my_decorator
def foo():
    print "foo"

@my_decorator
def bar(s):
    print "hello",s
    return s

@my_decorator
def foobar(x=1,y=2):
    print x,y
    return x + y

foo()
bar("world")
foobar(y=5)