🎯 Multiple Conditions

When your programs need to handle more than two possibilities, multiple conditions become essential. Python's elif statement allows you to check several conditions in sequence, creating sophisticated decision trees that can handle complex scenarios with many different outcomes.

Multiple conditions help you avoid deeply nested if statements and create cleaner, more readable code. Instead of checking conditions one inside another, you can list them in a clear, logical sequence.

# Multiple conditions with elif
grade = 85

if grade >= 90:
    letter = "A"
    print("Excellent work!")
elif grade >= 80:
    letter = "B"
    print("Good job!")
elif grade >= 70:
    letter = "C"
    print("You passed!")
elif grade >= 60:
    letter = "D"
    print("You need improvement.")
else:
    letter = "F"
    print("You failed.")

print(f"Your grade: {letter}")

🔄 The Elif Statement

The elif statement (short for "else if") allows you to check additional conditions after the initial if statement. Python evaluates elif conditions in order, executing the first one that's true and skipping the rest.

This sequential evaluation is important - once Python finds a true condition, it executes that block and skips all remaining elif and else clauses. This makes elif statements efficient and predictable.

# Elif statement evaluation order
time_of_day = 14  # 24-hour format

if time_of_day < 6:
    greeting = "Good night"
elif time_of_day < 12:
    greeting = "Good morning"
elif time_of_day < 18:
    greeting = "Good afternoon"
else:
    greeting = "Good evening"

print(f"{greeting}! It's {time_of_day}:00")

🧩 Complex Logical Conditions

You can combine multiple comparisons in a single condition using logical operators. This allows you to create sophisticated conditions that check several criteria simultaneously.

Complex conditions help you express nuanced decision logic without creating deeply nested if statements. Use parentheses to make complex conditions clear and readable.

# Complex logical conditions
age = 25
has_license = True
has_car = True
has_insurance = False

if age >= 18 and has_license and has_car and has_insurance:
    print("You can drive legally!")
elif age >= 18 and has_license:
    print("You can drive, but you need insurance and a car.")
elif age >= 18:
    print("You're old enough, but you need a license.")
else:
    print("You're too young to drive.")

# Complex condition with parentheses
temperature = 75
humidity = 45
if (temperature >= 70 and temperature <= 80) and (humidity >= 30 and humidity <= 50):
    print("Perfect weather conditions!")

🔀 Quick Multiple Conditions Practice

Let's practice using elif statements to handle multiple different conditions!

Hands-on Exercise

Practice using if, elif, and else statements to handle multiple conditions.

python

# Multiple Conditions Practice - Grade calculator!

# Grade based on score
score = 85

# TODO: Your code here: Complete the grade calculator
# 90-100: "A grade"
# 80-89: "B grade" 
# 70-79: "C grade"
# Below 70: "F grade"

if score >= 90:
    print("A grade")
# Add elif and else statements here

Solution and Explanation 💡

Click to see the complete solution

# Multiple Conditions Practice - Simple solution

# Grade based on score
score = 85

# Complete grade calculator
if score >= 90:
    print("A grade")
elif score >= 80:      # 80-89
    print("B grade")
elif score >= 70:      # 70-79
    print("C grade")
else:                  # Below 70
    print("F grade")

Key Learning Points:

📌 elif statement: Checks additional conditions after if
📌 Order matters: Conditions are checked from top to bottom
📌 Mutually exclusive: Only one condition can execute
📌 else catches all: Handles any remaining cases

🔗 Chained Comparisons

Python allows you to chain comparison operators in a natural way, making range checks and multiple comparisons more readable. This feature is unique to Python and makes certain conditions much cleaner.

Chained comparisons are especially useful for checking if a value falls within a specific range or meets multiple criteria simultaneously.

# Chained comparisons
temperature = 72
humidity = 45
score = 85

# Range checking with chained comparisons
if 68 <= temperature <= 78:
    print("Temperature is comfortable")

if 30 <= humidity <= 50:
    print("Humidity is ideal")

# Multiple comparisons vs chained
age = 25
if 18 <= age <= 65:  # Chained - more readable
    print("Working age (chained)")

if age >= 18 and age <= 65:  # Traditional - more verbose
    print("Working age (traditional)")

# Grade checking with chained comparisons
if 90 <= score <= 100:
    print("A grade")
elif 80 <= score < 90:
    print("B grade")
elif 70 <= score < 80:
    print("C grade")
else:
    print("Below C grade")

⚡ Conditional Expressions (Ternary Operator)

Python provides a concise way to write simple if-else statements in a single line using conditional expressions. This is useful for simple assignments based on conditions.

# Conditional expressions (ternary operator)
age = 20
status = "adult" if age >= 18 else "minor"
print(f"Status: {status}")

# Comparing with regular if-else
score = 85
if score >= 70:
    result = "pass"
else:
    result = "fail"

# Same logic with ternary operator
result_ternary = "pass" if score >= 70 else "fail"
print(f"Result: {result_ternary}")

# Multiple ternary operators (avoid nesting)
weather = "sunny"
activity = "beach" if weather == "sunny" else "indoor games"
print(f"Today's activity: {activity}")

# Using ternary in function calls
numbers = [1, 2, 3, 4, 5]
print("Even" if len(numbers) % 2 == 0 else "Odd", "count of numbers")