Is it correct to change the value of __name__
atribute of object like in the following examp开发者_如何学运维le:
>>>
>>> def f(): pass
...
>>> f.__name__
'f'
>>> b = f
>>> b.__name__
'f'
>>> b.__name__ = 'b'
>>> b
<function b at 0x0000000002379278>
>>> b.__name__
'b'
>>>
Changing a function's name doesn't make the new name callable:
>>> def f(): print 'called %s'%(f.__name__)
...
>>> f()
called f
>>> f.__name__ = 'b'
>>> f()
called b
>>> b()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
NameError: name 'b' is not defined
You'd have to define b
in order to call it. And as you saw, simply assigning b=f
doesn't define a new function.
Yes, you can change __name__
. I sometimes change the __name__
of a decorator instance to reflect the function it's decorating, e.g.
class CallTrace:
...
def __init__(self, f):
self.f = f
self.__name__ = f.__name__ + ' (CallTraced)'
I'm not asserting this is good practice, but it has helped me debug code in the past. The idea is if you decorate a function fn
, then type fn.__name__
at the prompt, you can see immediately that it's decorated.
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