Python ยท Chapter 5 of 45
Python Variables
A variable is a name that refers to a value. You create one by assigning: `x = 5`. Python figures out the type automatically.
Variable names must start with a letter or underscore and can contain letters, digits and underscores. They are case-sensitive.
Assignment
The `=` operator binds a name to a value. You can reassign the same name to a different type at any time.
Naming conventions
Use `snake_case` for variables and functions. Use `UPPER_CASE` for constants. Avoid single-letter names except for short loops.
Example 1 (python)
age = 21
name = "Ravi"
print(name, "is", age)Output
Ravi is 21Two variables of different types, printed together.
Example 2 (python)
x, y, z = 1, 2, 3
print(x + y + z)Output
6Multiple assignment in one line.
Key points
- No type declaration โ the value determines the type.
- Names are case-sensitive (`age` โ `Age`).
- Use `snake_case` for readability.
- Reserved keywords like `if`, `for`, `class` cannot be names.
๐ก Note: Descriptive names (`user_email`) beat cryptic ones (`ue`) every time.