Python Pandas – Filter 函數

測試環境為 CentOS 8 (虛擬機) 參考資料 – https://pandas.pydata.org/pandas-docs/version/0.19/generated/pandas.DataFrame.filter.html

透過 filter 函數搭配 regex (標準表示式) 可以依據 column , Row 名稱來搜尋.

安裝所需模組

[root@localhost ~]# pip install pandas

匯入模組

[root@localhost ~]# python3
Python 3.6.8 (default, Sep 10 2021, 09:13:53)
[GCC 8.5.0 20210514 (Red Hat 8.5.0-3)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import pandas as pd

建立測試用資料.

>>> df = pd.DataFrame({"one":[1, 4],"two":[2,5],"three":[3,6]}, index=["mouse", "rabbit"])
>>> df
        one  two  three
mouse     1    2      3
rabbit    4    5      6

依據欄位名稱來搜尋.

>>> df.filter(items=['one', 'three'])
        one  three
mouse     1      3
rabbit    4      6

配合 regex 來搜尋欄位.

>>> df.filter(regex='e$', axis=1)
        one  three
mouse     1      3
rabbit    4      6

>>> df.filter(regex='one|two', axis=1)
        one  two
mouse     1    2
rabbit    4    5

>>> df.filter(regex='.*o.*', axis=1)
        one  two
mouse     1    2
rabbit    4    5

使用 like + axis=0 可以搜尋 rows 列名稱.

>>> df.filter(like='bbi', axis=0)
        one  two  three
rabbit    4    5      6