将 Pandas DataFrame 列拆分为两列

Question

我正在做一个简单的网络抓取，DataFrame 项目。我有一个简单的 8x1 DataFrame，我正在尝试将其拆分为一个 8x2 DataFrame。到目前为止，这就是我的 DataFrame 的样子：

dframe = DataFrame(data, columns=['Active NPGL Teams'], index=[1, 2, 3, 4, 5, 6, 7, 8])

    Active NPGL Teams
1   Baltimore Anthem (2015–present)
2   Boston Iron (2014–present)
3   DC Brawlers (2014–present)
4   Los Angeles Reign (2014–present)
5   Miami Surge (2014–present)
6   New York Rhinos (2014–present)
7   Phoenix Rise (2014–present)
8   San Francisco Fire (2014–present)

我想添加一列“活跃年数”，并将“（2014 年至今）”、“（2015 年至今）”拆分为“活跃年数”列。如何拆分我的数据？

Answer 1

你可以使用

dframe['Active NPGL Teams'].str.split(r' (?=\()', expand=True)

                    0               1
1    Baltimore Anthem  (2015–present)
2         Boston Iron  (2014–present)
3         DC Brawlers  (2014–present)
4   Los Angeles Reign  (2014–present)
5         Miami Surge  (2014–present)
6     New York Rhinos  (2014–present)
7        Phoenix Rise  (2014–present)
8  San Francisco Fire  (2014–present)

关键是正则表达式r' (?=\()'，它仅在空格后跟一个左括号（前瞻断言）时才匹配。

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另一种方法（慢约 5% 但更灵活）是用户 Series.str.extract。

dframe['Active NPGL Teams'].str.extract(r'^(?P<Team>.+) (?P<YearsActive>\(.+\))$',
                                        expand=True)

                 Team     YearsActive
1    Baltimore Anthem  (2015–present)
2         Boston Iron  (2014–present)
3         DC Brawlers  (2014–present)
4   Los Angeles Reign  (2014–present)
5         Miami Surge  (2014–present)
6     New York Rhinos  (2014–present)
7        Phoenix Rise  (2014–present)
8  San Francisco Fire  (2014–present)