Python&Django: What does ** mean

Question

Possibly i know the following uses of **

Power

x ** y # x power y equivalent to pow(x,y)

Passing indefinite number of args

def sample(x, **other):
    print(x, other.keys)
sample(x=2,y=3,z=4)

But i don't understand when its used as follow( in Serializers)

def create(self, validated_data):
    return Comment(**validated_data)

Can someone give me a hint of what is happening there

score 4 · Accepted Answer · answered Dec 10 '16 at 13:19

It is the opposite of your second example. When in the definition of a function, the ** operator gathers all the named arguments and makes a dictionary. When calling a function, it takes a dictionary and breaks it into named arguments

So, if you have

values = {'x': 1, 'y': 2}
f(**values)

it is the equivalent of

f(x=1, y=2)

Python&Django: What does ** mean

1 Answers1