MenuBasedCalculator.py

################################
# Author: Rahim Siddiq
# Menu Based Calculator 
################################

def add():                        # Function Add
    return n1 + n2

def subtract():                   # Function Subtract
    return n1 - n2

def multiply():                   # Function Multiply
    return n1 * n2

def divide():                     # Function Divide
    return n1 / n2

def remainder():                  # Function Modulus / Remainder
    return n1 % n2

def integer_division():           # Function Integer Division
    return n1 // n2

def exponentiation():             # Function Exponentiation
    return n1 ** n2

def average():                    # Function Average
    return sum(a) / n

print("Please select the number of the function you wish to calculate:")
print("1.Add")
print("2.Subtract")
print("3.Multiply")
print("4.Divide")
print("5.Remainder")
print("6.Integer_Division")
print("7.Exponentiation")
print("8.Average")

cfunction = input("Enter Number of The Function: ")

if cfunction in ("1","2","3","4","5","6","7"):
    n1 = float(input("Enter first number: "))
    n2 = float(input("Enter second number: "))

if cfunction == "1":
    print(n1, "+", n2, "=", add())

elif cfunction == "2":
    print(n1, "-", n2, "=", subtract())

elif cfunction == "3":
    print(n1, "*", n2, "=", multiply())

elif cfunction == "4":
    if n2 == 0:
        print("Error: cannot divide by zero")
    else:
        print(n1, "/", n2, "=", divide())

elif cfunction == "5":
    if n2 == 0:
        print("Error: modulus by zero is undefined")
    else:
        print(n1, "%", n2, "=", remainder())

elif cfunction == "6":
    if n2 == 0:
        print("Error: integer division by zero")
    else:
        print(n1, "//", n2, "=", integer_division())

elif cfunction == "7":
    print(n1, "**", n2, "=", exponentiation())

elif cfunction == "8":
    n = int(input("How many numbers would you like to average? "))
    if n < 1:
        print("Please enter a value of at least 1.")
    else:
        a = []
        for i in range(n):
            val = float(input("Enter a number: "))
            a.append(val)
        print("Values entered", list(a), "Average:", average())

else:
    print("Please select the number of the function you would like to perform.")