How to Pass an Array to a Function in Python

Last Updated : 16 Jul, 2026

Arrays are often passed to functions so that multiple elements can be processed together instead of passing them one by one. A function can perform different operations on the array, such as traversing, searching, updating, or calculating values.

Using Python Array

Python's array module provides an array data structure that stores elements of the same data type. We can pass the entire array to a function just like any other object.

Python
from array import array

def show(a):
    for i in a:
        print(i)

arr = array('i', [10, 20, 30, 40])
show(arr)

Output
10
20
30
40

Explanation: array is passed as a single argument to the show() function, which iterates through all its elements using a for loop.

Using Python List

Lists are commonly passed to functions in Python. Once passed, the function can access, modify, or perform any operation on the list elements.

Python
def total(a):
    print(sum(a))

lst = [5, 10, 15, 20]
total(lst)

Output
50

Explanation: list is passed directly to the function, where the built-in sum() function calculates the total of all elements.

Using Variable-Length Arguments (*args)

When the number of values is not known in advance, *args allows multiple arguments to be passed to a function. Inside the function, these values are available as a tuple.

Python
def show(*a):
    for i in a:
        print(i)

show(10, 20, 30, 40)

Output
10
20
30
40

Explanation: values passed to show() are collected into a tuple using *args, allowing the function to process any number of arguments.

Using List Unpacking

If the data is already stored in a list, we can unpack the list while calling the function. Each element is passed as a separate argument.

Python
def show(a, b, c):
    print(a)
    print(b)
    print(c)

lst = [10, 20, 30]
show(*lst)

Output
10
20
30

Explanation: * operator unpacks the list, passing each element as an individual argument to the function. This is useful when the function expects a fixed number of parameters.

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