我有一个元组列表，并希望创建一个只包含元组中的一个字符串的实例的列表。

Question

我有一个元组列表：

[(1, 'Twilight Sparkle', 2, 'Fluttershy'), (1, 'Twilight Sparkle', 3,
'Applejack'), (1, 'Twilight Sparkle', 4, 'Pinkie Pie'), (1, 'Twilight
Sparkle', 5, 'Rarity'), (1, 'Twilight Sparkle', 6, 'Rainbow Dash'),
(1, 'Twilight Sparkle', 7, 'Princess Celestia'), (1, 'Twilight
Sparkle', 8, 'Princess Luna'), (2, 'Fluttershy', 3, 'Applejack'), (2,
'Fluttershy', 4, 'Pinkie Pie'), (2, 'Fluttershy', 5, 'Rarity'), (2,
'Fluttershy', 6, 'Rainbow Dash'), (2, 'Fluttershy', 7, 'Princess
Celestia'), (2, 'Fluttershy', 8, 'Princess Luna'), (3, 'Applejack', 4,
'Pinkie Pie'), (3, 'Applejack', 5, 'Rarity'), (3, 'Applejack', 6,
'Rainbow Dash'), (3, 'Applejack', 7, 'Princess Celestia'), (3,
'Applejack', 8, 'Princess Luna'), (4, 'Pinkie Pie', 5, 'Rarity'), (4,
'Pinkie Pie', 6, 'Rainbow Dash'), (4, 'Pinkie Pie', 7, 'Princess
Celestia'), (4, 'Pinkie Pie', 8, 'Princess Luna'), (5, 'Rarity', 6,
'Rainbow Dash'), (5, 'Rarity', 7, 'Princess Celestia'), (5, 'Rarity',
8, 'Princess Luna'), (6, 'Rainbow Dash', 7, 'Princess Celestia'), (6,
'Rainbow Dash', 8, 'Princess Luna'), (7, 'Princess Celestia', 8,
'Princess Luna')]

我想从它创建一个只有第一次出现字符串的列表，在这个例子中，我希望列表是：

[(1, 'Twilight Sparkle', 2, 'Fluttershy'), (3, 'Applejack', 4, 'Pinkie
Pie'),(5, 'Rarity', 6, 'Rainbow Dash'), (7, 'Princess Celestia', 8,
'Princess Luna')]

Answer 1

您可以保留已经使用过的元素的set。

只有在之前没有使用过任何元素的情况下，才向结果添加元组：

data = [(1, 'Twilight Sparkle', 2, 'Fluttershy'), (1, 'Twilight Sparkle', 3, 'Applejack'), (1, 'Twilight Sparkle', 4, 'Pinkie Pie'), (1, 'Twilight Sparkle', 5, 'Rarity'), (1, 'Twilight Sparkle', 6, 'Rainbow Dash'), (1, 'Twilight Sparkle', 7, 'Princess Celestia'), (1, 'Twilight Sparkle', 8, 'Princess Luna'), (2, 'Fluttershy', 3, 'Applejack'), (2, 'Fluttershy', 4, 'Pinkie Pie'), (2, 'Fluttershy', 5, 'Rarity'), (2, 'Fluttershy', 6, 'Rainbow Dash'), (2, 'Fluttershy', 7, 'Princess Celestia'), (2, 'Fluttershy', 8, 'Princess Luna'), (3, 'Applejack', 4, 'Pinkie Pie'), (3, 'Applejack', 5, 'Rarity'), (3, 'Applejack', 6, 'Rainbow Dash'), (3, 'Applejack', 7, 'Princess Celestia'), (3, 'Applejack', 8, 'Princess Luna'), (4, 'Pinkie Pie', 5, 'Rarity'), (4, 'Pinkie Pie', 6, 'Rainbow Dash'), (4, 'Pinkie Pie', 7, 'Princess Celestia'), (4, 'Pinkie Pie', 8, 'Princess Luna'), (5, 'Rarity', 6, 'Rainbow Dash'), (5, 'Rarity', 7, 'Princess Celestia'), (5, 'Rarity', 8, 'Princess Luna'), (6, 'Rainbow Dash', 7, 'Princess Celestia'), (6, 'Rainbow Dash', 8, 'Princess Luna'), (7, 'Princess Celestia', 8, 'Princess Luna')]

already_added = set()
result = []

for quad in data:
    if not any((x in already_added) for x in quad):
        for x in quad:
            already_added.add(x)
        result.append(quad)

print(result)
# [(1, 'Twilight Sparkle', 2, 'Fluttershy'), (3, 'Applejack', 4, 'Pinkie Pie'), (5, 'Rarity', 6, 'Rainbow Dash'), (7, 'Princess Celestia', 8, 'Princess Luna')]

请注意，此代码对应的是所需的输出，而不是问题中的描述。这个期望的输出更具有限制性，如果总是将某些元素耦合到已经看到的元素，那么有些元素将根本不会被添加。适用于：

data = [(1, 'a', 2, 'b'), (1, 'a', 3, 'c'), (2, 'b', 4, 'd')]

产出如下：

[(1, 'a', 2, 'b')]

看不到3，4，c或d！