Python IDLE restart

Question

I am trying to run my code inside of IDLE Python i wrote everything is correct but sadly i cannot run. it restarts without any reason.

def calculator():
    operation = input('''
Please Enter one of These:
+ for adding
- for minize
* for multiply
/ for devision
''')

    num1 = int(input('Num 1 : '))
    num2 = int(input('Num 2 : '))

    if operation == '+':
        print(' {} + {} = ' . format(num1 , num2))
        print(num1 + num2)

    elif operation == '-':
        print(' {} - {} = ' . format(num1 , num2))
        print(num1 - num2)

    elif operation == '*':
        print(' {} * {} = ' . format('num1 , num2'))
        print(num1 * num2)

    elif operation == '/':
        print(' {} / {} = ' . format('num1 , num2'))
        print(num1 / num2)

    else:
        print('Error')

    again()

def again():
    calc_again = input('''
Wanna Try Again:
if yes please type Y and if no Please Type N
''')
    if calc_again.upper() == 'Y':
        calculator()

    elif calc_again.upper() == 'N':
        print('Good Bye')
    else:
        again()

Answer 1

You will have to call the calculator() method to start the program (check the last line)..

def calculator():
    operation = input('''
Please Enter one of These:
+ for adding
- for minize
* for multiply
/ for devision
''')

    num1 = int(input('Num 1 : '))
    num2 = int(input('Num 2 : '))

    if operation == '+':
        print(' {} + {} = ' . format(num1 , num2))
        print(num1 + num2)

    elif operation == '-':
        print(' {} - {} = ' . format(num1 , num2))
        print(num1 - num2)

    elif operation == '*':
        print(' {} * {} = ' . format('num1 , num2'))
        print(num1 * num2)

    elif operation == '/':
        print(' {} / {} = ' . format('num1 , num2'))
        print(num1 / num2)

    else:
        print('Error')

    again()

def again():
    calc_again = input('''
Wanna Try Again:
if yes please type Y and if no Please Type N
''')
    if calc_again.upper() == 'Y':
        calculator()

    elif calc_again.upper() == 'N':
        print('Good Bye')
    else:
        again()

calculator() #call method