Calling a function with unknown number of parameters Python

In python, we can pass an unknown amount of arguments into the function using asterisk notation.

Let's try to create a function sum_up() with an unknown number of arguments.

def sum_up(*args):
    s = 0
    for i in args:
        s += i
    return s

As you see, an argument with an asterisk before will collect all arguments given to this function inside a tuple called args.

We can call this function that way:

sum_up(5, 4, 6)  # Gives 15

But if we want to sum up elements of a list and we need to pass it into the function as arguments...

We can try the following:

l = [5, 4, 6]

This won't give an effect we need: args of sum_up will look like ([5, 4, 6],). To do what we want, we need to put an asterisk before the argument we're passing:

sum_up(*l)  # Becomes sum_up(5, 4, 6)

All you need to do is collect all arguments you want to pass in a list and then put an asterisk before this list passed as an argument inside a call:

args = [service ['good '] , tip ['average']]