Python - Arrays (Complete Guide for Beginners)

 In Python, an array is a collection of items stored at contiguous memory locations. Arrays are used to store multiple values in a single variable, similar to lists, but with some important differences.

Python does not have built-in array support like C or Java, but it provides arrays through the array module and also uses lists as a flexible alternative.

In this tutorial, you will learn Python arrays, how they work, and how to use them effectively.

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What is an Array?

An array is a data structure that stores:

• Multiple values
• Same data type items (in traditional arrays)

Example Concept:

Index:   0   1   2   3
Array:  10  20  30  40

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Creating Arrays in Python

To use arrays in Python, we import the array module.

Syntax:

import array

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Example 1: Creating an Integer Array

import array as arr

numbers = arr.array('i', [10, 20, 30, 40, 50])

print(numbers)

Output:

array('i', [10, 20, 30, 40, 50])

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Array Type Codes

Python arrays require a type code to define data type.

Type Code	Type	Description
'i'	Integer	Signed integer
'f'	Float	Floating point
'd'	Double	Floating point
'u'	Unicode	Character

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Example 2: Float Array

import array as arr

prices = arr.array('f', [10.5, 20.3, 30.7])

print(prices)

Output:

array('f', [10.5, 20.299999237060547, 30.700000762939453])

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Accessing Array Elements

You can access elements using index numbers.

Example:

import array as arr

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

print(numbers[0])
print(numbers[2])

Output:

10
30

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Modifying Array Elements

Example:

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

numbers[1] = 99

print(numbers)

Output:

array('i', [10, 99, 30, 40])

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Looping Through Arrays

Example:

for num in numbers:
    print(num)

Output:

10
99
30
40

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Adding Elements to Array

Use append() to add one item.

Example:

numbers.append(50)

print(numbers)

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Inserting Elements in Array

Use insert() to add at a specific position.

Example:

numbers.insert(1, 15)

print(numbers)

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Removing Elements from Array

Use remove() to delete a value.

Example:

numbers.remove(99)

print(numbers)

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Pop Method in Arrays

Removes an element by index.

Example:

numbers.pop(2)

print(numbers)

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Array Length

Use len() to get the number of elements.

Example:

print(len(numbers))

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Real-World Example: Student Marks

import array as arr

marks = arr.array('i', [85, 90, 78, 88])

total = 0

for mark in marks:
    total += mark

print("Total Marks:", total)

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Real-World Example: Product Prices

import array as arr

prices = arr.array('f', [99.99, 149.50, 200.75])

for price in prices:
    print(price)

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Array vs List in Python

Feature	Array	List
Data Type	Same type only	Mixed types
Performance	Faster	Slower
Module Required	Yes	No
Flexibility	Less	More

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When to Use Arrays?

Use arrays when:

• You need fast processing
• You work with large numeric data
• You need memory efficiency
• Data type is the same

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Common Mistakes

Mistake 1: Mixing Data Types

❌ Wrong:

arr.array('i', [10, "hello", 30])

✔ Correct:

arr.array('i', [10, 20, 30])

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Mistake 2: Forgetting Type Code

❌ Wrong:

arr.array([10, 20, 30])

✔ Correct:

arr.array('i', [10, 20, 30])

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Array Methods Summary

Method	Description
append()	Add item at end
insert()	Add item at index
remove()	Remove value
pop()	Remove index
index()	Find index
reverse()	Reverse array

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Practice Exercise 1

Create an array of 5 integers and print all values.

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Practice Exercise 2

Insert a number at index 2 and remove the last element.

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Conclusion

Python arrays are powerful for handling structured numeric data efficiently.

You learned:

• How to create arrays using array module
• How to access and modify elements
• How to add and remove items
• Differences between arrays and lists
• Real-world usage examples

Arrays are very useful in data processing, scientific computing, and performance-critical applications.