Python – Variable Names

1. What is a Variable Name?

A variable name is the name of the box where we store data.

Example:

Here:

• age is the variable name

• 25 is the value

2. Why Variable Names Are Important

Good variable names make your code:
✔ Easy to read
✔ Easy to understand
✔ Easy to fix later

Bad names make code confusing 😕

3. Rules for Variable Names in Python

Python has some simple rules.
You must follow these rules, or Python will give an error.

✅ Rule 1: Start with a Letter or _

✔ Allowed:

❌ Not Allowed:

✅ Rule 2: Use Only Letters, Numbers, and _

✔ Allowed:

❌ Not Allowed:

✅ Rule 3: No Python Keywords

You cannot use Python reserved words.

❌ Wrong:

✔ Correct:

✅ Rule 4: Variable Names Are Case-Sensitive

These are two different variables.

4. Good Variable Naming Style (Best Practice)

Python uses snake_case.

Good Names 👍

Bad Names 👎

(These work, but are hard to understand.)

5. Short vs Meaningful Names

Bad Example

Good Example

Meaningful names are better.

6. Multiple Variable Names

Example

7. Common Beginner Mistakes

❌ Using Spaces

✔ Correct:

❌ Starting with Number

✔ Correct:

8. Practice Examples

Example 1: Correct Names

Example 2: Fix the Wrong Names

❌ Wrong:

✔ Correct:

9. Summary (Variable Names)

✔ Variable name is the name of the data box
✔ Must start with letter or _
✔ No spaces or special symbols
✔ No Python keywords
✔ Use meaningful names

📘 Perfect for Beginner eBook

This chapter is ideal for:

• Python beginner books

• School students

• Self-learners

If you want next, I can write:

• Python Data Types

• Python Operators

• if–else statements

• Loops (for, while)

• Practice questions with answers

Just tell me 😊