Star / Asterisks Operator ( * ) in Python – 1

1. Unpacking iterables into a list/tuple

In addition to serving as the symbol for multiplication, the star operator (*) in Python has several other applications. The first application is unpacking iterables into a list/tuple

Example: Adding (appending) elements to an array

>>> n = [2, ,3, 4, 5, 6, 1]
>>> n
[2, 3, 4, 5, 6, 1]
>>> m = [n, 2]
>>> m
[[2, 3, 4, 5, 6, 1], 2]

instead,

>>> n = [2,3,4,5,6,1]
>>> n
[2, 3, 4, 5, 6, 1]
>>> m = [*n, 2]
>>> m
[2, 3, 4, 5, 6, 1, 2]

Another example:

>>> chars = ['a', 'b', 'c', 'd']
>>> print(chars)
['a', 'b', 'c', 'd']
>>> print(chars[0], chars[1], chars[2], chars[3])
a b c d
>>>print(*chars)
a b c d

2. Packing function arguments

The star operator can be used for packing arguments sent to a function. In other words, we can develop functions that can accept any number of arguments. For instance,

>>> def collect_all(*n):
return sum(n)

>>> collect_all(1)
1
>>> collect_all(1,2,3)
6
>>>

The star or asterisk operator has other applications that we will discuss in another post.