檢查列是否包含列表中的字符串，並輸出該字符串

Question

我正在嘗試檢查一列列表中的字符串，如果該字符串存在，則為 output，到目前為止我已經完成了一半

k = ['a', 'e','o']
data = pd.DataFrame({"id":[1,2,3,4,5],"word":["cat","stick","door","dog","lung"]})

   id   word
0   1    cat
1   2  stick
2   3   door
3   4    dog
4   5   lung

我試過這個

data["letter"] = data['word'].apply(lambda x: any([a in x for a in k]))

試圖得到這個

   id   word  letter
0   1    cat    a
1   2  stick   
2   3   door    o
3   4    dog    o
4   5   lung   

但我得到這個

   id   word  letter
0   1    cat    True
1   2  stick   False
2   3   door    True
3   4    dog    True
4   5   lung   False

Answer 1

您可以將內置的next function與生成器表達式一起使用。 next function 的第二個參數是default ，如果迭代器耗盡，將返回它。

data["letter"] = data["word"].apply(
    lambda x: next(
        (a for a in k if a in x), ""
    )
)

完整代碼：

>>> import pandas as pd
>>>
>>> k = ["a", "e", "o"]
>>> data = pd.DataFrame(
...     {
...         "id": [1, 2, 3, 4, 5],
...         "word": [
...             "cat",
...             "stick",
...             "door",
...             "dog",
...             "lung",
...         ],
...     }
... )
>>>
>>> data["letter"] = data["word"].apply(
...     lambda x: next(
...         (a for a in k if a in x), ""
...     )
... )
>>> print(data)
   id   word letter
0   1    cat      a
1   2  stick
2   3   door      o
3   4    dog      o
4   5   lung