Python Pandas：ディレクトリ内のファイルを同様のファイル名でグループ化し、データフレームを特定の順序で連結します

それはあなたがこれをやりたいと言っているpandasので、ここにpandas解決策があります。

fnames = ['After_Source1_Receiver1.csv',
          'After_Source1_Receiver2.csv',
          'Before_Source1_Receiver1.csv',
          'Before_Source1_Receiver2.csv',
          'During1_Source1_Receiver1.csv',
          'During1_Source1_Receiver2.csv',
          'During2_Source1_Receiver1.csv',
          'During2_Source1_Receiver2.csv']

df = pd.DataFrame(fnames, columns=['names'])

最終結果をどうしたいのかわかりませんが、これがグループ化の方法です。

pattern = r'Source(\d+)_Receiver(\d+)'
for _, g in pd.concat([df, df['names'].str.extract(pattern)], axis=1).groupby([0,1]):
    print(g.names)

0      After_Source1_Receiver1.csv
2     Before_Source1_Receiver1.csv
4    During1_Source1_Receiver1.csv
6    During2_Source1_Receiver1.csv
Name: names, dtype: object
1      After_Source1_Receiver2.csv
3     Before_Source1_Receiver2.csv
5    During1_Source1_Receiver2.csv
7    During2_Source1_Receiver2.csv
Name: names, dtype: object