#default imports
import os #OS, for Windows version!
import time
#default variables
welcome = 'welcome to CLI'
hello = 'hello'
#clear the screen
def cleardef():
    os.system('cls')
#type2continue prompt
def type2conti():
    uselessvar = input('type something to continue..')
    cli()
def wwhat():
    print('test')
    cli()
#CLI
def cli():
    cleardef()
    global command
    print(welcome)
    #ERROR
    #---------------------------------------
    #take away the # to see the random error
    #print(hello)
    #---------------------------------------
    time.sleep(0.1)
    command = input('type your command>>> ')
    if command == 'change welcome':
        #changewelcome
        def changewelcome():
            global welcome
            welcome = input('what would you like your welcome message to be?>>> ')
        changewelcome()
        cli()
        #about
    elif command == 'about':
        cleardef()
        print("tbh pretty useless")
        time.sleep(1)
        cli()
    #calculator
    elif command == 'calculator':
        #setting a calculator def so it can run back if the "if" statement runs else
        def calculatordef():
            global firstn
            global secondn
            global sign
            firstn = int(input('first number>>> '))
            secondn = int(input('second number>>> '))
            sign = input('sign>>> ')
        calculatordef()
        if sign == '+':
            number = firstn + secondn
            print(number)
            type2conti()
        elif sign == '-':
            number = firstn - secondn
            print(number)
            type2conti()
        elif sign == '*':
            number = firstn * secondn
            print(number)
            type2conti()
            cli()
        if sign == '/':
            number = firstn / secondn
            print(number)
            type2conti()
        else:
            #invalid signs for calculator
            print('"',sign,'"', 'invald sign')
            time.sleep(1)
            type2conti()
    #if the user types anything else..
    else:
        print('"',command,'"', 'invalid command')
        type2conti()
cli()