python - 提取单词周围的单词并将结果插入数据框列中

Question

我有一个数据框 df，包含 3 列，如下所示:

company | year | text  
Apple   | 2016 |"The Company sells its products worldwide through its..."  

我想在df['text']中搜索“products”，并提取“products”前后的3个单词，并将前后3个单词插入到数据框，分别为 df['before'] 和 df['after']。

这是我到目前为止所做的:

m = re.search(r'((?:\w+\W+){,3})(products)\W+((?:\w+\W+){,3})', df['text'])       
merge['searchText'])    
if m:
    l = [ x.strip().split() for x in m.groups()]
df['left'], df['right'] = l[0], l[2]  

但是，我收到此消息:

TypeError: expected string or buffer

我怎样才能让它发挥作用？

Answer 1

使用pd.Series.str.extract

pat = '(?P<before>(?:\w+\W+){,3})products\W+(?P<after>(?:\w+\W+){,3})'
new = df.text.str.extract(pat, expand=True)

new

               before                     after
0  Company sells its   worldwide through its...

您可以使用新列创建新数据框

df.assign(**new)

  company  year                                               text                     after              before
0   Apple  2016  The Company sells its products worldwide throu...  worldwide through its...  Company sells its