使用 python 根据特定条件合并两个表

Question

我有两个 table（table1，table2）如下：

table1:

ID	Filename
12345	12345.txt
12346	12346.txt
12347	12347.txt
12348	12348.txt
12349	12349.txt
12350	12350.txt

table2：包含存在 table 1 个文件的路径

Path
/table/text3/12349.txt
/table/text1/12345.txt
/table/text2/12346.txt
/table/text1/12350.txt
/table/text3/12347.txt
/table/text1/12348.txt

如何合并这两个文件，使路径和文件名匹配。到目前为止我尝试了什么？

pd.concat([table1, table2])

我也试过pd.merge，但它与文件名不匹配。我该如何解决？

期望的输出：

ID	Filename	Path
12345	12345.txt	/table/text1/12345.txt
12346	12346.txt	/table/text2/12346.txt
12347	12347.txt	/table/text3/12347.txt
12348	12348.txt	/table/text1/12348.txt
12349	12349.txt	/table/text3/12349.txt
12350	12350.txt	/table/text1/12350.txt

Answer 1

您可以提取 Filename 然后进行合并：

merged_df = df2.assign(Filename = df2['Path'].str.rsplit('/', 1).str[-1]).merge(df1, on = 'Filename')

选项通过 pathlib:

from pathlib import Path
merged_df = df2.assign(Filename = df2['Path'].apply(lambda x: Path(x).name)).merge(df1, on = 'Filename')

输出：

                     Path   Filename     ID
0  /table/text3/12349.txt  12349.txt  12349
1  /table/text1/12345.txt  12345.txt  12345
2  /table/text2/12346.txt  12346.txt  12346
3  /table/text1/12350.txt  12350.txt  12350
4  /table/text3/12347.txt  12347.txt  12347
5  /table/text1/12348.txt  12348.txt  12348

Answer 2

您可以通过 .assign() and use the resulting copy of df2 with newly added column to merge with df1 using .merge() 在公共列 Filename 上创建临时列 Filename 在 df2 上，如下所示：

df_merge = df1.merge(df2.assign(Filename=df2['Path'].str.split('/').str[-1]), on='Filename')

结果：

print(df_merge)



      ID   Filename                    Path
0  12345  12345.txt  /table/text1/12345.txt
1  12346  12346.txt  /table/text2/12346.txt
2  12347  12347.txt  /table/text3/12347.txt
3  12348  12348.txt  /table/text1/12348.txt
4  12349  12349.txt  /table/text3/12349.txt
5  12350  12350.txt  /table/text1/12350.txt

编辑

如果在df2中没有匹配条目的情况下仍想显示df1的条目，可以使用带参数how='left'的左合并，如下：

df_merge = df1.merge(df2.assign(Filename=df2['Path'].str.split('/').str[-1]), on='Filename', how='left')

结果：

如果路径 /table/text3/12347.txt 丢失：

      ID   Filename                    Path
0  12345  12345.txt  /table/text1/12345.txt
1  12346  12346.txt  /table/text2/12346.txt
2  12347  12347.txt                     NaN
3  12348  12348.txt  /table/text1/12348.txt
4  12349  12349.txt  /table/text3/12349.txt
5  12350  12350.txt  /table/text1/12350.txt

使用 python 根据特定条件合并两个表

Combine two tables based on certain criteria using python

python

filenames

path

pandas

编辑