python - 在 python 数据框中查找正则表达式

Question

我遇到一个问题

我有一个名为雇主的数据框，如下所示:

employer
------------
wings brand activation i pvt ltd
hofincons infotech &industrial services pvt .ltd
bharat fritz werner bangalore
kludi rak indpvt ltd.

另一个数据框，它将雇主名称映射到看起来像这样的类别(称之为 pincode):

Index   Name                                    FINAL_CATEGORY
68781   central board of excise and customs     cat b
68782   c a g hotels pvt ltd                    cat b
68783   avaneetha textiles pvt ltd              cat a
68784   trendy wheels pvt ltd                   cat a+
68785   wings brand activations india pvt ltd   cat b

现在我想模仿类似的东西:

pincode[pincode['Compnay Name'].str.contains('wings brand activation i pvt ltd')]

Compnay Name    FINAL_CATEGORY
____________________________________

pincode[pincode['Compnay Name'].str.contains('wings brand activation i pvt')]

Compnay Name    FINAL_CATEGORY
____________________________________

pincode[pincode['Compnay Name'].str.contains('wings brand activation i')]


Compnay Name    FINAL_CATEGORY
____________________________________

pincode[pincode['Compnay Name'].str.contains('wings brand activation')]

        Name                                    FINAL_CATEGORY
68785   wings brand activations india pvt ltd   cat b

如您所见，对于每个字符串，我都会从字符串末尾开始减少长度，直到最后一个空格，然后进行搜索。

上面的内容需要放入循环中(我认为是正则表达式)。因此，对于雇主表中的每个条目，它都会搜索整个 pincode 范围并找出最接近的匹配项。如果没有返回 nan。

提前致谢，由于这个问题有点难以用语言表达，请要求任何澄清。

Answer 1

您可以使用迭代方法，如下所示:

def find_substr(employer, pincode):
    employer = employer.set_index("employer")
    for words in employer.index.map(str.split):
        length = len(words)
        found = False
        while length > 0 and not found:
            substr = ' '.join(words[:length]).replace('(', '\(')
            mask = pincode.Name.str.contains(substr)
            if mask.any():
                employer.loc[' '.join(words), 'cat'] = pincode.loc[mask, 'FINAL_CATEGORY'].values[0]
                found = True
            length -= 1
    employer = employer.reset_index()
    return employer

employer = find_substr(employer, pincode)
print(employer)

                                           employer    cat
0                  wings brand activation i pvt ltd  cat b
1  hofincons infotech &industrial services pvt .ltd    NaN
2                     bharat fritz werner bangalore    NaN
3                              kludi rak indpvt ltd    NaN