Simple Python Programs using if and if else

 # Program to check if a number is positive or negative

num = float(input("Enter a number: "))

if num > 0:

    print("The number is positive.")

elif num == 0:

    print("The number is zero.")

else:

    print("The number is negative.")

# Program to check if a number is even or odd

num = int(input("Enter a number: "))

if num % 2 == 0:

    print("The number is even.")

else:

    print("The number is odd.")

# Program to find the maximum of three numbers

num1 = float(input("Enter the first number: "))

num2 = float(input("Enter the second number: "))

num3 = float(input("Enter the third number: "))

if num1 >= num2 and num1 >= num3:

    print("The maximum number is:", num1)

elif num2 >= num1 and num2 >= num3:

    print("The maximum number is:", num2)

else:

    print("The maximum number is:", num3)

# Program to check eligibility to vote

age = int(input("Enter your age: "))

if age >= 18:

    print("You are eligible to vote.")

else:

    print("You are not eligible to vote.")

# Program to calculate grades based on marks

marks = float(input("Enter your marks: "))

if marks >= 90:

    grade = 'A'

elif 80 <= marks < 90:

    grade = 'B'

elif 70 <= marks < 80:

    grade = 'C'

elif 60 <= marks < 70:

    grade = 'D'

else:

    grade = 'F'

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

# Program to check if a year is a leap year

year = int(input("Enter a year: "))

if (year % 4 == 0 and year % 100 != 0) or (year % 400 == 0):

    print(f"{year} is a leap year.")

else:

    print(f"{year} is not a leap year.")

# Program to implement a simple calculator

num1 = float(input("Enter the first number: "))

operator = input("Enter an operator (+, -, *, /): ")

num2 = float(input("Enter the second number: "))

if operator == '+':

    result = num1 + num2

elif operator == '-':

    result = num1 - num2

elif operator == '*':

    result = num1 * num2

elif operator == '/':

    if num2 != 0:

        result = num1 / num2

    else:

        result = "Error: Division by zero"

else:

    result = "Error: Invalid operator"

print(f"Result: {result}")

# Program to check if a string is a palindrome

def is_palindrome(s):

    s = s.lower()

    reversed_s = s[::-1]

    

    if s == reversed_s:

        print("The string is a palindrome.")

    else:

        print("The string is not a palindrome.")

user_input = input("Enter a string: ")

is_palindrome(user_input)

# Program for a simple guess the number game

import random

secret_number = random.randint(1, 10)

guess = int(input("Guess the secret number (between 1 and 10): "))

if guess == secret_number:

    print("Congratulations! You guessed the correct number.")

else:

    print(f"Sorry, the correct number was {secret_number}. Try again.")

# Program to convert temperature from Celsius to Fahrenheit or vice versa

def celsius_to_fahrenheit(celsius):

    return (celsius * 9/5) + 32

def fahrenheit_to_celsius(fahrenheit):

    return (fahrenheit - 32) * 5/9

choice = input("Choose conversion (C to F or F to C): ").upper()

if choice == 'C':

    celsius = float(input("Enter temperature in Celsius: "))

    result = celsius_to_fahrenheit(celsius)

    print(f"{celsius}°C is equal to {result}°F.")

elif choice == 'F':

    fahrenheit = float(input("Enter temperature in Fahrenheit: "))

    result = fahrenheit_to_celsius(fahrenheit)

    print(f"{fahrenheit}°F is equal to {result}°C.")

else:

    print("Invalid choice. Please enter 'C' or 'F'.")

# Program to check if a number is prime

def is_prime(number):

    if number <= 1:

        return False

    for i in range(2, int(number**0.5) + 1):

        if number % i == 0:

            return False

    return True

num = int(input("Enter a number: "))

if is_prime(num):

    print(f"{num} is a prime number.")

else:

    print(f"{num} is not a prime number.")

# Program to find the factorial of a number

def factorial(n):

    if n == 0 or n == 1:

        return 1

    else:

        return n * factorial(n - 1)

num = int(input("Enter a number: "))

result = factorial(num)

print(f"The factorial of {num} is {result}.")

# Program for a simple Rock, Paper, Scissors game

import random

choices = ["Rock", "Paper", "Scissors"]

user_choice = input("Enter your choice (Rock, Paper, Scissors): ").capitalize()

computer_choice = random.choice(choices)

print(f"Computer's choice: {computer_choice}")

if user_choice == computer_choice:

    print("It's a tie!")

elif (

    (user_choice == "Rock" and computer_choice == "Scissors") or

    (user_choice == "Paper" and computer_choice == "Rock") or

    (user_choice == "Scissors" and computer_choice == "Paper")

):

    print("You win!")

else:

    print("You lose!")