39        print("You have to type a number!")
 40        sys.exit()
 41operator1 = input("Type out your operator: ")
 42    #operator1 == '+' or '-' or '*' or '/' or '^' or 'sqrt' or 'log' or 'sin' or 'cos' or 'tan' or ('tan^-1') or ('cos^-1') or ('sin^-1') 43
 44if operator1 in ch:
 45    pass