Let's talk about adding an asterisk (**) before lists and dictionaries in Python

Why are there asterisks (**) in front of Python lists and dictionaries? The following article will talk to you about the reasons for adding an asterisk (**) before lists and dictionaries in Python. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to everyone.

In Python, the single asterisk * and the double asterisk ** are except for "multiplication" and "power" values. In addition to operators, it also plays an important role in the operations of lists, tuples, and dictionaries.

1. Add an asterisk in front of the list and tuple *

The effect of adding an asterisk in front of the list is to Unpack (unpacke) into multiple independent parameters and pass them into the function.

def add(a, b):
    return a + b

data = [7, 8]
print(add(*data)) # 15

import numpy as np
print(np.arange(3,6)) # [3 4 5]

list2 = [3, 6]
print(np.arange(*list2)) # [3 4 5]

2. Add two asterisks in front of the dictionary (dict) **

Add two asterisks in front of the dictionary to interpret the dictionary Open as an independent element as a formal parameter.

'''
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'''
def add(a, b):
    return a + b

data = {'a':7, 'b':8}
print(add(**data)) # 15

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