Basic python script for performing addition, subtraction, multiplication, percentage calculation, and division

calc.py

def add(x, y):
  """Returns the sum of x and y."""
  return x + y

def subtract(x, y):
  """Returns the difference of x and y."""
  return x - y

def multiply(x, y):
  """Returns the product of x and y."""
  return x * y

def calculate_percentage(x, y):
  """Returns the percentage of x in y."""
  return (x / y) * 100

def divide(x, y):
  """Returns the result of dividing x by y (handles division by zero)."""
  if y == 0:
    print("Error: Cannot divide by zero.")
    return None
  return x / y

def main():
  print("Welcome to the Multifunction Calculator!")

  while True:
    # Get user input for operation
    operation = input("Choose an operation (+, -, *, %, /): ")

    # Get user input for numbers
    try:
      num1 = float(input("Enter the first number: "))
      num2 = float(input("Enter the second number: "))
    except ValueError:
      print("Invalid input. Please enter numbers only.")
      continue

    # Perform operation based on user choice
    if operation == "+":
      result = add(num1, num2)
      print(f"{num1} + {num2} = {result}")
    elif operation == "-":
      result = subtract(num1, num2)
      print(f"{num1} - {num2} = {result}")
    elif operation == "*":
      result = multiply(num1, num2)
      print(f"{num1} * {num2} = {result}")
    elif operation == "%":
      result = calculate_percentage(num1, num2)
      print(f"{num1} is {result}% of {num2}")
    elif operation == "/":
      result = divide(num1, num2)
      if result:
        print(f"{num1} / {num2} = {result}")
    else:
      print("Invalid operation. Please choose +, -, *, %, or /.")

    choice = input("Do you want to perform another calculation? (y/n): ")
    if choice.lower() != "y":
      break

if __name__ == "__main__":
  main()