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

PythonListArgument Unpacking

Python Problem Overview

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))

Python Solutions

Solution 1 - Python

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)

Solution 2 - Python

I think you mean the * unpacking operator:

>>> l = [1,2,3,4,5]
>>> def add(a,b,c,d,e):
...    print(a,b,c,d,e)
...
>>> add(*l)
1 2 3 4 5

Solution 3 - Python

Use the * operator. So add(*x) would do what you want.

See this other SO question for more information.

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Content TypeOriginal AuthorOriginal Content on Stackoverflow
Questionfalek.marcinView Question on Stackoverflow
Solution 1 - PythonCat Plus PlusView Answer on Stackoverflow
Solution 2 - PythonTim PietzckerView Answer on Stackoverflow
Solution 3 - PythonarunkumarView Answer on Stackoverflow