pythonを使って簡単な計算機を作るコード

print('Simple calculator!')

first_number = input('First number? ')

if first_number.isnumeric() == False:
    print('Please input a number.')
    exit()

operation = input('Operation? ')

second_number = input('Second number? ')

if second_number.isnumeric() == False:
    print('Please input a number.')
    exit()

first_number = int(first_number)
second_number = int(second_number)

result = 0
if operation == '+':
    result = first_number + second_number
    label = 'sum'
elif operation == '-':
    result = first_number - second_number
    label = 'difference'
elif operation == '*':
    result = first_number * second_number
    label = 'product'
elif operation == '/':
    result = first_number / second_number
    label = 'quotient'
elif operation == '**':
    result = first_number ** second_number
    label = 'exponent'
elif operation == '%':
    result = first_number % second_number
    label = 'modulus'
else:
    print('Operation not recognized.')
    exit()

print(label + ' of ' + str(first_number) + ' ' + operation + ' ' + 
str(second_number) + ' equals ' + str(result))