或操作符在while循环中

Question

因此，我想一直询问用户要使用哪种货币，直到他们输入“ USD”或“ GEL”为止，但这似乎行不通。帮助将不胜感激

import datetime

db = [
    {
        'product': 'cola',
        'price': {
            'USD': '2',
            'GEL': '6'
        },
        'amount': 20,
        'validity': '17/12/2019'
    },
    {
        'product': 'cake',
        'price': {
            'USD': '3',
            'GEL': '9'
        },
        'amount': 15,
        'validity': '17/12/2019'
    },
    {
        'product': 'tea',
        'price': {
            'USD': '1',
            'GEL': '3'
        },
        'amount': 14,
        'validity': '17/12/2019'
    },
]

amount_of_product = {}
validity_of_product = {}
prices_of_product = {}

for i in db:
    amount_of_product.update({i["product"]: i["amount"]})
    validity_of_product.update({i["product"]: i["validity"]})
    prices_of_product.update({i["product"]: i["price"]})

adLoop = True
totalGEL = 0
totalUSD = 0


while adLoop:
    user_input = input("Please enter a product name: ").lower()
    if user_input in amount_of_product.keys() and validity_of_product.keys():
        print(f"Currently, we have {amount_of_product[user_input]} amount of {user_input} left, "
              f"which are valid through {validity_of_product[user_input]}")

    user_input_two = input("Please enter the amount: ")
    while not user_input_two.isdigit():
        user_input_two = input("Please enter a number: ")
    user_input_three = input("In which currency would you like to pay in?(GEL or USD): ").upper()
    while user_input_three != "GEL" or not user_input_three != "USD":
        user_input_three = input("In which currency would you like to pay in:?(GEL or USD only) ").upper()
    price = prices_of_product[user_input][user_input_three]
    total = int(user_input_two) * int(price)

    if user_input_three == "GEL":
        totalGEL += total
        print(f"Your order is: {user_input_two} {user_input} and total price for it is: {total}₾")
    elif user_input_three == "USD":
        totalUSD += total
        print(f"Your order is: {user_input_two} {user_input} and total price for it is: {total}$")

    stop_or_order = input("Would you like to add anything else?: ")
    if stop_or_order == "yes":
        adLoop = True
    elif stop_or_order == "no":
        adLoop = False

print(test)

这就是我被困住的地方。在这种情况下，一个语句为true，并且如果用户输入“ USD”，而仅输入“ GEL”，它就不会中断。如果用户输入其中之一，我希望它停止。

user_input_three = input("In which currency would you like to pay in?(GEL or USD): ").upper()
    while user_input_three != "GEL" or not user_input_three != "USD":
        user_input_three = input("In which currency would you like to pay in:?(GEL or USD only)