Mastering the Basics: How to Define Variables in Python

Learn how to define variables in Python with our step-by-step guide. Discover the basics of variable declaration and how to use them in your code. Start coding like a pro today!

Updated October 18, 2023

In Python, a variable is a container that holds a value. You can think of it like a box that stores a particular piece of data. To define a variable in Python, you simply assign a value to it using the assignment operator (=). Here are some examples:

Basic Variable Definition

Let’s start with some basic examples of defining variables in Python:

name = "John"  # Define a variable named "name" and assign it the value "John"
age = 30         # Define a variable named "age" and assign it the value 30

In this example, we define two variables: name and age. We assign the value "John" to name, and the value 30 to age.

List Variables

You can also define lists in Python. A list is a collection of items that can be of any data type, including other lists. Here’s an example:

fruits = ["apple", "banana", "orange"]  # Define a list named "fruits" and assign it the values ["apple", "banana", "orange"]

In this example, we define a list called fruits and assign it three strings: "apple", "banana", and "orange".

Nesting Variables

You can also define variables within other variables. This is called nesting. Here’s an example:

outer = {"inner": ["apple", "banana"]}  # Define an outer dictionary with a nested list

In this example, we define an outer dictionary named outer with a nested list inside it. The inner list contains two strings: "apple" and "banana".

Using Augmented Assignment

You can also use augmented assignment to define variables. This is a shorthand way of reassigning a variable without creating a new one. Here’s an example:

x = 10
x += 5  # Define x and assign it the value 15

In this example, we define x to be 10, and then use augmented assignment to add 5 to it, so x now has the value 15.

Defining Variables with Context Manager

You can also define variables using a context manager. Here’s an example:

with open("example.txt", "r") as f:
    content = f.read()  # Define a variable named "content" and assign it the value of the file "example.txt"

In this example, we use a context manager to open a file named "example.txt" in read mode ("r"). The with statement ensures that the file is properly closed when we exit the block. Inside the block, we define a variable called content and assign it the value of the file using the read() method.