What does ** (double star/asterisk) and * (star/asterisk) do for parameters?

Question

In the following method definitions, what does the `*` and `**` do for `param2`? def foo(param1, *param2): def bar(param1, **param2):

Answer 1

A single * will swallow up any remaining non-keyword arguments and pass them as a list for the function. ** will do the same thing for keyword arguments. Consider the following example

def this(*args, **kwargs):

for arg in args:

print(arg)

for key, value in kwargs.items():

print("{} = {}".format(key, value))

this(1, 2, 3 a=3, b=4, c=6)

The output of the above command will be

1

2

3

a = 3

b = 4

c = 6

This allows you to define functions that take a variable number of arguments.