Python asterisk before function [duplicate]

Question

I am following this tutorial:

http://www.pyimagesearch.com/2015/04/20/sorting-contours-using-python-and-opencv/#comment-405768

and in one of the lines there is the function:

(cnts, boundingBoxes) = zip(*sorted(zip(cnts, boundingBoxes),
        key=lambda b:b[1][i], reverse=reverse))

I want to know what is the use of the asterisk before the sorted function call.

Answer 1

Asterisk is unpacking operator:

>>> list(range(3, 6))            # normal call with separate arguments
[3, 4, 5]
>>> args = [3, 6]
>>> list(range(*args))            # call with arguments unpacked from a list
[3, 4, 5]

More about unpacking operator:

https://docs.python.org/3/tutorial/controlflow.html#unpacking-argument-lists