Calculator in Python

import os



def showMenu(): # Function that display the menu
    print('1. Addition')
    print('2. Subtraction')
    print('3. Multiplication')
    print('4. Division')
    print('5. Exit\n')


def myChoice(): # Take your choice in input
    c = input('')
    return int(c)


def select(c):  # This function prints the choice you entered
    if c == 1:
        print('\nAddition')
    elif c == 2:
        print('\nSubtraction')
    elif c == 3:
        print('\nMultiplication')
    elif c == 4:
        print('\nDivision')
    else:
        exit(1) # Forces the exit if we enter the value 5


def calc(a, b, c):  # Returns the result of the caclculations
    if c == 1:
        return a+b
    elif c == 2:
        return a-b
    elif c == 3:
        return a*b
    elif c == 4:
        return a/b


def signFunc(c):  # Change the sign depending on your choice
    if c == 1:
        return' + '
    elif c == 2:
        return ' - '
    elif c == 3:
        return ' * '
    elif c == 4:
        return ' / '


mainLoop = 1;

while mainLoop : # Infinite loop
    sign = ' + ';
    showMenu()
    c = myChoice()
    select(c)
    sign = signFunc(c)

    print('Enter the first number: ')
    entry1 = input('');  # First entry
    print('Enter the second number: ')
    entry2 = input('');  # Second entry

    entry1 = float(entry1) # Convert our entries into floats
    entry2 = float(entry2)

    result = calc(entry1, entry2, c)

    print('\n' + str(entry1) + sign + str(entry2) + ' = ' + str(result) + '\n\n')

os.system('Pause')