Python Variable Naming Rules

In Python programming, variable names serve as identifiers for storing data. A variable may have a brief identifier like x or y, or a more descriptive name such as age, carname, or total_volume.

Official Rules for Naming Variables in Python

• Variable names must begin with a letter (A–Z, a–z) or an underscore (_).
• They cannot begin with a digit (0–9).
• Only alphanumeric characters and underscores are allowed (A–Z, a–z, 0–9, and _).
• Variable names are case-sensitive (e.g., age, Age, and AGE are distinct).
• Reserved Python keywords cannot be used as variable names.

Legal Examples of Python Variable Names

myvar = "John"
my_var = "John"
_my_var = "John"
myVar = "John"
MYVAR = "John"
myvar2 = "John"
    

Illegal Examples of Variable Names

2myvar = "John"
my-var = "John"
my var = "John"
    

Note: Python treats variable names as case-sensitive. This means that myVar and MyVar refer to different variables.

Multi-Word Variable Naming Conventions

For variables consisting of multiple words, readability is essential. Python supports several naming conventions to improve clarity:

Camel Case

Each word after the first begins with a capital letter:

myVariableName = "John"

Pascal Case

Each word starts with a capital letter:

MyVariableName = "John"

Snake Case

Words are separated using underscores:

my_variable_name = "John"

These naming conventions enhance code readability and are commonly used in different programming contexts.

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