python - 删除 Pandas 数据框中多次出现的重复值

Question

请告诉我如何在Python中获取其HashCode出现多次的ImgFileNames。 注意:仅保留第一个出现的位置并删除剩余的位置，即使该值出现在中间、最后或任何位置。

我有一个如下所示的数据框:

ImgFileName         HashCodes
Img_0001 - Copy.tif 162a47470f021a60
Img_0001.tif        162a47470f021a60
Img_0002.tif        1b5b5b1aa638dac8
Img_0003.tif        adadadadadadadad
Img_0004.tif        adadadadadadadad
Img_0005 - Copy.tif a5b8648c8c666670
Img_0005.tif        a5b8648c8c666670
Img_0006.tif        71b392da6a699392
Img_0007.tif        71b392da6a699392
Img_0008.tif        b1b1f2fa6bf97292
Img_0009.tif        86e82ae4c8b6c9c9
Img_0010 - Copy.tif 86e8aae4c8b6c9c9
Img_0010.tif        86e8aae4c8b6c9c9

我想要如下输出:

ImgFileName         HashCodes
Img_0001 - Copy.tif 162a47470f021a60
Img_0003.tif        adadadadadadadad
Img_0005 - Copy.tif a5b8648c8c666670
Img_0006.tif        71b392da6a699392
Img_0009.tif        86e82ae4c8b6c9c9

Answer 1

您需要boolean indexing与 duplicated - 首先过滤所有重复项，第二次过滤重复项的最后一个值或重复项的第一个值 (keep='last'):

df =df[ df.duplicated('HashCodes', keep=False) & df.duplicated('HashCodes')]
print (df)
     ImgFileName         HashCodes
1   Img_0001.tif  162a47470f021a60
4   Img_0004.tif  adadadadadadadad
6   Img_0005.tif  a5b8648c8c666670
8   Img_0007.tif  71b392da6a699392
12  Img_0010.tif  86e8aae4c8b6c9c9

或者:

df =df[ df.duplicated('HashCodes', keep=False) & df.duplicated('HashCodes', keep='last')]
print (df)
           ImgFileName         HashCodes
0   Img_0001 -Copy.tif  162a47470f021a60
3         Img_0003.tif  adadadadadadadad
5   Img_0005 -Copy.tif  a5b8648c8c666670
7         Img_0006.tif  71b392da6a699392
11  Img_0010 -Copy.tif  86e8aae4c8b6c9c9