Arrays vs. Python Lists

At this point, the concept of arrays is clear, including what they are, how indexing works, how they are stored in memory, and how size and dimensions affect their structure. The next step is learning how to work with arrays in Python.

Python is unusual among programming languages because it does not have a built-in array type. Instead, it offers two options: the array module and a Python list. In this lesson, we will explore, understand what sets them apart, and learn when to use each.

The array module

As we already know, Python doesn't provide us with a built-in array type the way languages like C or Java do. Instead, it provides an array module that allows us to create true typed arrays. By true typed array, we mean an array that can only store elements of a single, fixed data type. Once we declare an array as an integer array, every element in it must be an integer. We cannot mix integers with strings, floats, or elements of any other data type. This is exactly what we meant when we described arrays as a collection of elements of the same type, stored in contiguous memory locations.

This homogeneous nature is not arbitrary. It is what allows the computer to store all elements directly in contiguous memory, calculate the address of any element instantly using the address formula, and process the data efficiently. Every slot in the array is guaranteed to be the same size, which is what makes all of this possible.

Implementation

The array module is a part of Python’s standard library, which means it comes preinstalled with Python. To use the array module, we first need to import it:

Once imported, we can create an array using the array keyword. We pass it two arguments: a type code, which specifies the data type the array ...