使用过滤器过滤数据框的两列

Question

我有以下类型的数据框：

df = pd.DataFrame(
    {
        "Name": [
            [
                " VerbundmÃ¶rtel ",
                " Compound Mortar ",
                " Malta per stucchi e per incollaggio ",
            ],
            [" StoLevell In Absolute ", " StoLevell In Absolute "],
            [
                " Anhydrit-FlieÃ\x9festrich ",
                " Anhydrite Flowing Screed ",
                " Massetto a base di anidrite ",
            ],
        ],
        "NAME_FILE": [
            "AdhesiveCoveringPlaster_2",
            "AdhesiveMortarLevellInForAEVERO_720",
            "AnhydriteFlowingScreed_20",
        ],
    }
)

我正在尝试根据某些关键字过滤两列。我的想法是获得一个数据框，其中我有两列，但只有满足条件的值。

select_materials = {
    "Plaster": list(
        filter(
            lambda x: "Hist".casefold() in x.casefold()
            or "Plaster".casefold() in x.casefold()
            or "Gips".casefold() in x.casefold(),
            df.FILE,
        )
    )
}

为了方便起见，我只插入了整个文件中的几行，但希望我的objective是清楚的。结果应该是一个数据框，其中过滤器应用于两列。如果同一行的任一列中都存在过滤词，则应保留整行。

Answer 1

与其使用 filter，我建议使用更惯用的方法。

假设您要过滤单词 "Mortar":

# Simply define two filtering masks, since one column contains lists of strings,
# whereas the other one simply contains strings
mask1 = df["Name"].apply(lambda x: "Mortar".casefold() in "".join(x).casefold())
mask2 = df["NAME_FILE"].apply(lambda x: "Mortar".casefold() in x.casefold())

# If a filtered word is present in either column of the same row,
# then the whole row should be kept
print(df.loc[mask1 | mask2, :])

                                                Name                            NAME_FILE
0  [ VerbundmÃ¶rtel ,  Compound Mortar ,  Malta p...            AdhesiveCoveringPlaster_2
                                ^^^^^^
1  [ StoLevell In Absolute ,  StoLevell In Absolu...  AdhesiveMortarLevellInForAEVERO_720
                                                              ^^^^^^

使用过滤器过滤数据框的两列

Filtering two columns of a dataframe with filter

python

filter

dataframe

pandas

case-folding