A function in Python takes two kinds of arguments: positional arguments, and keyword arguments. def foo(a, b, c): pass # Arguments passed posi

A function in Python takes two kinds of arguments: positional arguments, and keyword arguments. def foo(a, b, c): pass # Arguments passed positionally: foo(1, 2, 3) # or passed by keyword: foo(a=1, b=2, c=3) Now, say you want to make that second call somewhat dynamically, and you have the dict: a_dict = {'a': 1, 'b': 2, 'c': 3} You can make that second foo call: foo(**a_dict) # because of the value of a_dict, expands to: # foo(a=1, b=2, c=3) Functions themselves can take only positional arguments, only keyword arguments, or really, any combination of them. Here is a decent SO question and answer[1] that might help, a bit about it in the tutorial[2], and last, the formal documentation[3]. [1]: https://stackoverflow.com/questions/1419046/python-normal-arguments-vs-keyword-arguments https://stackoverflow.com/questions/1419046/python-normal-ar... [2]: https://docs.python.org/2/tutorial/controlflow.html#keyword-arguments https://docs.python.org/2/tutorial/controlflow.html#keyword-... [3]: https://docs.python.org/2/reference/expressions.html#grammar-token-call https://docs.python.org/2/reference/expressions.html#grammar...