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

问题

This question already has an answer here:

• Use of *args and **kwargs [duplicate] 11 answers

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))

回答1:

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) 

回答2:

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

回答3:

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

See this other SO question for more information.

来源：https://stackoverflow.com/questions/7527849/how-to-extract-parameters-from-a-list-and-pass-them-to-a-function-call