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Embrace keyword arguments in Python Consider using the * operator to require those arguments be specified as keyword arguments. And remember that you can accept arbitrary keyword arguments to the functions you define and pass arbitrary keyword arguments to the functions you call by using the ** operator.
To extract the number and names of the arguments from a function or function[something] to return ("arg1", "arg2"), we use the inspect module. The given code is written as follows using inspect module to find the parameters inside the functions aMethod and foo.
The __name__ variable (two underscores before and after) is a special Python variable. It gets its value depending on how we execute the containing script. Sometimes you write a script with functions that might be useful in other scripts as well. In Python, you can import that script as a module in another script.
The phrase "keyword only args" in Python is a bit ambiguous - usually I take it to mean args passed in to a **kwarg parameter. However, the inspect module seems to make a distinction between **kwarg and something called "keyword only arguments".
From the docs:
inspect.getfullargspec(func)
Get the names and default values of a Python function’s arguments. A named tuple is returned:
FullArgSpec(args, varargs, varkw, defaults, kwonlyargs, kwonlydefaults, annotations)
argsis a list of the argument names.varargsandvarkware the names of the*and**arguments orNone. defaults is an n-tuple of the default values of the last n arguments, or None if there are no default arguments.kwonlyargsis a list of keyword-only argument names.kwonlydefaultsis a dictionary mapping names fromkwonlyargsto defaults.annotationsis a dictionary mapping argument names to annotations.
So the inspect module has something called kwonlyargs and kwonlydefaults. What does this mean in an actual function signature? If you have a function signature that accept a **kwarg argument, you can't really know the names of the keyword arguments until runtime, because the caller can basically just pass any arbitrary dictionary. So, what meaning does kwonlyargs have in the context of a function signature - which is what the inspect.getfullargspec provides.
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