if-elif-else Condition

Used when there are multiple mutually exclusive conditions to check in sequence.

Syntax

if condition1:
    statement(s)
elif condition2:
    statement(s)
elif condition3:
    statement(s)
else:
    statement(s)   # runs only if none of the above matched

Conditions are evaluated top to bottom; the first True branch runs and the rest are skipped.

marks = 72

if marks >= 90:
    grade = "A+"
elif marks >= 75:
    grade = "A"
elif marks >= 60:
    grade = "B"
elif marks >= 40:
    grade = "C"
else:
    grade = "Fail"

print("Grade:", grade)   # Grade: B

Flowchart

Example: Simple calculator using elif

a, b, op = 10, 5, '*'

if op == '+':
    print(a + b)
elif op == '-':
    print(a - b)
elif op == '*':
    print(a * b)
elif op == '/':
    print(a / b)
else:
    print("Invalid operator")

There is no switch/case statement in Python (before 3.10); if-elif-else is the traditional way to handle multi-way branching. Python 3.10+ introduced match-case as an alternative.