Calculator Code in Python

 # define function for addition

def add(x, y):
    return x + y

# define function for subtraction
def subtract(x, y):
    return x - y

# define function for multiplication
def multiply(x, y):
    return x * y

# define function for division
def divide(x, y):
    return x / y

# main program
print("Select operation.")
print("1.Add")
print("2.Subtract")
print("3.Multiply")
print("4.Divide")

# take input from the user
choice = input("Enter choice (1/2/3/4): ")

num1 = float(input("Enter first number: "))
num2 = float(input("Enter second number: "))

if choice == '1':
    print(num1, "+", num2, "=", add(num1, num2))

elif choice == '2':
    print(num1, "-", num2, "=", subtract(num1, num2))

elif choice == '3':
    print(num1, "*", num2, "=", multiply(num1, num2))

elif choice == '4':
    print(num1, "/", num2, "=", divide(num1, num2))
    
else:
    print("Invalid input")

To use this code, simply copy and paste it into a Python interpreter or text editor, and 
run it. The program will prompt you to select an operation 
(addition, subtraction, multiplication, or division), 
and then ask you to enter two numbers. Based on your input, it will perform 
the selected operation and display the result.