available_parts = ["computer",

"monitor",

"keyboard",

"mouse",

"mouse-mat",

"hdmi cable",

"dvd drive"

]

# valid_choices = [str(i) for i in range(1, len(available_parts)+1)]

valid_choices = []

for i in range (1, len(available_parts)+1):

valid_choices.append(str(i))

print(valid_choices)

current_choice = "-"

computer_parts = [] # create an empty list

while current_choice != "0":

if current_choice in valid_choices:

index = int(current_choice) - 1

chosen_part = available_parts[index]

if chosen_part in computer_parts:

print("Removing {}".format(current_choice))

computer_parts.remove(chosen_part)

else:

computer_parts.append(chosen_part)

print("Adding {}".format(current_choice))

print("Your list now contais {}".format(computer_parts))

else:

print("Please add options from the list below: ")

for number, part in enumerate(available_parts):

print("{0}: {1}".format(number+1, part))

current_choice = input()

print(computer_parts)