I am trying to decorate a class
def decorate_module(Module):
class Wrapper(Module):
def __init__(self, cfg):
self.c = create_c(**cfg)
super().__init__()
return Wrapper
While the code works, it gives a class named "Wrapper" instead of the name of the original module. When it comes to function decoration, one can use @wraps in this situation. I tried the same thing for class (by writing it just above class Wrapper(Module): but got an error.
What is the proper way to do this? A python built-in decorator @dataclass seems to be handling this well. I wonder how it works.. Is there a helper function like @wraps? Or should I manually overwrite __name__? If so, what are the full list of such "double-underscore "properties?
(EDIT) my original purpose
Given a class that does not take any arguments in __init__, I would like to decorate it to take an argument "cfg", do something (create_c), and store it as an attribute.
To be precise, my decorator will actually take "create_c" as an argument (I omitted this in the above code since additional nesting would make it verbose). Then, I am thinking of using it as follows.
@decorate_module(create_fn1)
class Module1:
...
@decorate_module(create_fn2)
class Module2:
...
There is no built-in equivalent to functools.wraps for a class, but you can copy yourself the dunder attributes of the class being wrapped, which include __doc__, __name__, __qualname__ and __module__, as documented.
def decorate_module(Module):
class Wrapper(Module):
def __init__(self, cfg):
self.c = create_c(**cfg)
super().__init__()
for attr in '__doc__', '__name__', '__qualname__', '__module__':
setattr(Wrapper, attr, getattr(Module, attr))
return Wrapper