How to extract parameters from a list and pass them to a function call

falek.marcin picture falek.marcin · Sep 23, 2011 · Viewed 33.9k times · Source

What is a good, brief way to extract items from a list and pass them as parameters to a function call, such as in the example below?

Example:

def add(a,b,c,d,e):
    print(a,b,c,d,e)

x=(1,2,3,4,5)

add(magic_function(x))

Answer

Cat Plus Plus picture Cat Plus Plus · Sep 23, 2011

You can unpack a tuple or a list into positional arguments using a star.

def add(a, b, c):
    print(a, b, c)

x = (1, 2, 3)
add(*x)

Similarly, you can use double star to unpack a dict into keyword arguments.

x = { 'a': 3, 'b': 1, 'c': 2 }
add(**x)