Attaching a decorator to all functions within a class

python class oop decorator class-method
dochead picture dochead · Aug 12, 2010 · Viewed 16.9k times · Source

I don't really need to do this, but was just wondering, is there a way to bind a decorator to all functions within a class generically, rather than explicitly stating it for every function.

I suppose it then becomes a kind of aspect, rather than a decorator and it does feel a bit odd, but was thinking for something like timing or auth it'd be pretty neat.

Answer

Duncan picture Duncan · Aug 12, 2010

The cleanest way to do this, or to do other modifications to a class definition, is to define a metaclass.

Alternatively, just apply your decorator at the end of the class definition:

class Something:
   def foo(self): pass

for name, fn in inspect.getmembers(Something):
    if isinstance(fn, types.UnboundMethodType):
        setattr(Something, name, decorator(fn))

For Python 3 replace types.UnboundMethodType with types.FunctionType.

In practice of course you'll want to apply your decorator more selectively. As soon as you want to decorate all but one method you'll discover that it is easier and more flexible just to use the decorator syntax in the traditional way.

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