如何在 while 循環中退出 for 循環並返回頂部？

Question

while True:
    new_move = input('Enter the coordinates: ')

    # check if cell is already occupied
    for i, el in enumerate(location):
        if new_move == el and cells[i] != '_':
            print('This cell is occupied! Choose another one!')
            break

    # check if new_move contains non-numerical values
    if not new_move.replace(' ', '').isdigit():
        print('You should enter numbers!')
        continue

    # check if new_move goes beyond 3
    if int(new_move[0]) > 3 or int(new_move[2]) > 3:
        print('Coordinates should be from 1 to 3!')
        continue

    # retrieve index of new_move that matches given coordinate
    for i, el in enumerate(location):
        if new_move == el and cells[i] == '_':
            # replace given index with 'X'
            new_cells = cells[:i] + 'X' + cells[i + 1:]
            # print new board state
            print('---------')
            print(f"| {' '.join(new_cells[0:3])} |")
            print(f"| {' '.join(new_cells[3:6])} |")
            print(f"| {' '.join(new_cells[6:9])} |")
            print('---------')
            

*重新編輯，因為我在上一個問題中省略了重要信息

OG問題：

如何退出 for 循環並返回到 while 循環的開頭（即再次要求 new_move 輸入）？ 目前，只有當我滿足另外兩個 if 語句時，代碼才會循環，而不是 for 循環中的 if 語句。 它只是直接跳到break，而不是循環回到起點。 我無法成功地將 continue 放在 for 循環中的任何位置。

我通過實施 user212514 的解決方案解決了這個問題。 但是現在我遇到的問題是，當最終的 for 循環完成/滿足時，我沒有退出 while 循環。 我不能在那里放置一個 break 語句而不弄亂其他東西。

Answer 1

您可以在for中使用break ：

while True:
    new_move = input('Enter the coordinates: ')

    # check if cell is already occupied
    for i, el in enumerate(location):
        if new_move == el and cells[i] != '_':
            print('This cell is occupied! Choose another one!')
            break

    # check if new_move contains non-numerical values
    if not new_move.replace(' ', '').isdigit():
        print('You should enter numbers!')
        continue

    # check if new_move goes beyond 3
    if int(new_move[0]) > 3 or int(new_move[2]) > 3:
        print('Coordinates should be from 1 to 3!')
        continue

修改后的問答

聽起來你會想要使用一個變量來防止在for之后評估if s。

while True:
    new_move = input('Enter the coordinates: ')
    good_coordinates = True
    for i, el in enumerate(location):
        if new_move == el and cells[i] != '_':
            print('This cell is occupied! Choose another one!')
            good_coordinates = False
            break

    if not good_coordinates:
        continue

    # execute your other if statements

Answer 2

您應該將檢查單元是否被占用的循環轉換為 boolean function 以便您可以根據其返回值使用continue ，就像您在主循環的 rest 中所做的那樣。

def is_occupied(position, location):
    for i, el in enumerate(location):
        if position == el and cells[i] != '_':
            return true

    return false

while True:
    new_move = input('Enter the coordinates: ')

    # check if cell is already occupied
    if is_occupied(new_move, location):
        print('This cell is occupied! Choose another one!')
        continue

    # check if new_move contains non-numerical values
    if not new_move.replace(' ', '').isdigit():
        print('You should enter numbers!')
        continue

    # check if new_move goes beyond 3
    if int(new_move[0]) > 3 or int(new_move[2]) > 3:
        print('Coordinates should be from 1 to 3!')
        continue