decorator_factory - Tools for making decorators

decorator_factory(fun)

Decorator to make parentheses optional when applying a decorator factory which has optional arguments.

Parameters:fun (func) – Function that returns a decorator Returns:Decorator factory which, if it is called with a single callable parameter, returns a wrapped function instead of a decorator Return type:func

Important

The factory’s signature should:

• Allow it to be called with no arguments
• Not allow it to be called with a single positional argument that is callable.

Example

>>> from functools import wraps
>>> @decorator_factory
... def print_when_called(print_done=False):
...     def decorator(fun):
...         @wraps(fun)
...         def wrapped(*args, **kwargs):
...             print('calling {}'.format(fun.__name__))
...             retval = fun(*args, **kwargs)
...             if print_done:
...                 print('done')
...             return retval
...         return wrapped
...     return decorator
>>> @print_when_called(print_done=True)  # decorated with args
... def my_fun_print_done():
...     pass
>>> @print_when_called()  # decorated with parentheses, no args
... def my_fun_decorated_empty_parentheses():
...     pass
>>> @print_when_called  # decorated without parentheses
... def my_fun_decorated_no_parentheses():
...     pass
>>> my_fun_print_done()
calling my_fun_print_done
done
>>> my_fun_decorated_empty_parentheses()
calling my_fun_decorated_empty_parentheses
>>> my_fun_decorated_no_parentheses()
calling my_fun_decorated_no_parentheses