Variables & Assignment

A variable is a name that refers to a value. Assignment uses = (read it as "becomes", not "equals"):

age = 21
name = "Minh"

Variables let programs remember. Once assigned, use the name anywhere below:

price = 5
quantity = 3
total = price * quantity   # 15
print(total)

Naming rules (and taste)

• Names may contain letters, digits, and underscores: user_name, score2.
• They cannot start with a digit or contain spaces.
• Case matters: total and Total are different names.
• Style: use snake_case — lowercase with underscores. Future-you reads names as documentation.

Reassignment

Variables point to values; pointing can change:

score = 10
score = score + 5   # now 15

Python evaluates the right side first (10 + 5), then re-points the name.