Language

Conditionalstatements

Source: 2-Control Flow/Conditionalstatements.ipynb

Start here — no coding background needed

What you will learn

Make the computer choose different actions based on a condition.

In simple words

`if` runs code only when a test is true. `else` is the backup when it is false. Indentation (spaces) shows what belongs inside.

Think of it like this

If rain → take umbrella, else → take sunglasses.

Words to know:

if / else — Two paths — one runs when test is true, other when false
Indent — Spaces at start of line — shows code inside if/else

Learn how programs make decisions and repeat tasks — like daily habits.

Easy example — try this first

Easy example — run this first. Change values and press Run again.

Runs in your browser via Pyodide — no server. First run may take a few seconds.

Reference notes (from full bootcamp)

Optional — deeper detail for when you are ready

Conditional Statements (if, elif, else)

Video Outline:

Introduction to Conditional Statements
if Statement
else Statement
elif Statement
Nested Conditional Statements
Practical Examples
Common Errors and Best Practices

Reference example

Output

Expected (from notebook):
You are allowed to vote in the elections

Runs in your browser via Pyodide — no server. First run may take a few seconds.

Reference example

Output

Expected (from notebook):
True

Runs in your browser via Pyodide — no server. First run may take a few seconds.

Reference example

Output

Expected (from notebook):
You are a minor

Runs in your browser via Pyodide — no server. First run may take a few seconds.

Reference example

Output

Expected (from notebook):
You are a teenager

Runs in your browser via Pyodide — no server. First run may take a few seconds.

Example HCL

## Nested Condiitonal Statements

# You can place one or more if, elif, or else statements inside another if, elif, or else statement to create nested conditional statements.

## number even ,odd,negative

num=int(input("Enter the number"))

if num>0:
    print("The number is positive")
    if num%2==0:
        print("The number is even")
    else:
        print("The number is odd")

else:
    print("The number is zero or negative")

Browser practice only — full example needs Python on your computer (files, Flask, threads, etc.).

Example HCL

## Practical Examples

## Determine if a year is a leap year using nested condition statement

year=int(input("Enter the year"))

if year%4==0:
    if year%100==0:
        if year%400==0:
            print(year,"is a leap year")
        else:
            print(year,"is not a leap year")
    else:
        print(year,"is a leap year")

else:
    print(year,"is not a leap year")

Browser practice only — full example needs Python on your computer (files, Flask, threads, etc.).

Example HCL

## Assignment
## Simple Calculator program
# Take user input
num1 = float(input("Enter first number: "))
num2 = float(input("Enter second number: "))
operation = input("Enter operation (+, -, *, /): ")

# Perform the requested operation
if operation == '+':
    result = num1 + num2
elif operation == '-':
    result = num1 - num2
elif operation == '*':
    result = num1 * num2
elif operation == '/':
    if num2 != 0:
        result = num1 / num2
    else:
        result = "Error! Division by zero."
else:
    result = "Invalid operation."

print("Result:", result)

Browser practice only — full example needs Python on your computer (files, Flask, threads, etc.).

Example HCL

### Determine the ticket price based on age and whether the person is a student.
# Ticket pricing based on age and student status

# Take user input
age = int(input("Enter your age: "))
is_student = input("Are you a student? (yes/no): ").lower()

# Determine ticket price
if age < 5:
    price = "Free"
elif age <= 12:
    price = "$10"
elif age <= 17:
    if is_student == 'yes':
        price = "$12"
    else:
        price = "$15"
elif age <= 64:
    if is_student == 'yes':
        price = "$18"
    else:
        price = "$25"
else:
    price = "$20"

print("Ticket Price:", price)

Browser practice only — full example needs Python on your computer (files, Flask, threads, etc.).

Complex Example 3: Employee Bonus Calculation

Calculate an employee's bonus based on their performance rating and years of service.

Example HCL

# Employee bonus calculation

# Take user input
years_of_service = int(input("Enter years of service: "))
performance_rating = float(input("Enter performance rating (1.0 to 5.0): "))

# Determine bonus percentage
if performance_rating >= 4.5:
    if years_of_service > 10:
        bonus_percentage = 20
    elif years_of_service > 5:
        bonus_percentage = 15
    else:
        bonus_percentage = 10
elif performance_rating >= 3.5:
    if years_of_service > 10:
        bonus_percentage = 15
    elif years_of_service > 5:
        bonus_percentage = 10
    else:
        bonus_percentage = 5
else:
    bonus_percentage = 0

# Calculate bonus amount
salary = float(input("Enter current salary: "))
bonus_amount = salary * bonus_percentage / 100

print("Bonus Amount: ${:.2f}".format(bonus_amount))

Browser practice only — full example needs Python on your computer (files, Flask, threads, etc.).

Complex Example 4: User Login System

A simple user login system that checks the username and password.

Example HCL

# User login system

# Predefined username and password
stored_username = "admin"
stored_password = "password123"

# Take user input
username = input("Enter username: ")
password = input("Enter password: ")

# Check login credentials
if username == stored_username:
    if password == stored_password:
        print("Login successful!")
    else:
        print("Incorrect password.")
else:
    print("Username not found.")

Browser practice only — full example needs Python on your computer (files, Flask, threads, etc.).

Practice test — try yourself

Write code, press Check. Wrong answer shows the correct code to copy & run.

marks = 55. If marks >= 50 print Pass, else print Fail.