Registrar decorator

registrar.py

"""                                                                             
Registrar decorator can be used to add objects (function and classes) to the    
registry.                                                                       
                                                                                
>>> reg = Registrar()                                                           
>>> @reg('foo')                                                                 
... def foo():                                                                  
...     print 'foo'                                                             
...                                                                             
>>> @reg('bar')                                                                 
... def bar():                                                                  
...     print 'bar'                                                             
...                                                                             
>>> reg.registry                                                                
{'foo': <function foo at 0x...>, 'bar': <function bar at 0x...>}                
>>> reg.registry['foo']()                                                       
foo                                                                             
>>> reg.registry['bar']()
bar
"""
class Registrar(object):

    def __init__(self):
        self.registry = {}

    def __call__(self, key):
        def wrapper(obj):
            self.registry[key] = obj
            return obj                                                          
        return wrapper