On Mon, 29 Jun 2009 18:01:29 -0700, David Hirschfield wrote: > I'm having a little problem with some python metaprogramming. I want to > have a decorator which I can use either with functions or methods of > classes, which will allow me to swap one function or method for another. > It works as I want it to, except that I want to be able to do some > things a little differently depending on whether I'm swapping two > functions, or two methods of a class. > > Trouble is, it appears that when the decorator is called the function is > not yet bound to an instance, so no matter whether it's a method or > function, it looks the same to the decorator.
Then: * use a naming convention to recognise methods (e.g. check if the first argument is called "self" by looking at function.func_code.co_varnames); * use two different decorators, or a decorator that takes an extra "method or function argument"; * play around with the class metaclass and see if you can do something special (and probably fragile); * do the replacements after the class is created without decorator syntax, e.g.: Class.method1 = swapWith(Class.method2)(Class.method1) > This simple example illustrates the problem: [snip] No it doesn't. It appears to work perfectly, from what I can guess you're trying to accomplish. Have you considered a possibly simpler way of swapping methods/functions? >>> def parrot(): ... print "It's pining for the fjords." ... >>> def cheeseshop(): ... print "We don't stock Cheddar." ... >>> parrot, cheeseshop = cheeseshop, parrot >>> >>> parrot() We don't stock Cheddar. >>> cheeseshop() It's pining for the fjords. Admittedly, this doesn't let you do extra processing before calling the swapped functions, but perhaps it will do for what you need. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
