问题描述
我有一个熊猫数据框如下:
I have a pandas dataframe as follows:
A B C 1 2 x 1 2 y 3 4 z 3 5 x
我希望只剩下 1 行在特定列**享相同值的行.在上面的示例中,我的意思是列 A 和 B.换句话说,如果列 A 和 B 的值在数据框中多次出现,则应该只保留一行(哪一行无关紧要).
I want that only 1 row remains of rows that share the same values in specific columns. In the example above I mean columns A and B. In other words, if the values of columns A and B occur more than once in the dataframe, only one row should remain (which one does not matter).
FWIW:所谓重复行的最大数量(即列A和B相同)为2.
FWIW: the maximum number of so called duplicate rows (that is, where column A and B are the same) is 2.
结果应该是这样的:
A B C 1 2 x 3 4 z 3 5 x
或
A B C 1 2 y 3 4 z 3 5 x
推荐答案
使用 drop_duplicates 和参数 subset,为了只保留最后重复的行添加 keep='last':p>
Use drop_duplicates with parameter subset, for keeping only last duplicated rows add keep='last':
df1 = df.drop_duplicates(subset=['A','B']) #same as #df1 = df.drop_duplicates(subset=['A','B'], keep='first') print (df1) A B C 0 1 2 x 2 3 4 z 3 3 5 x
<小时>
df2 = df.drop_duplicates(subset=['A','B'], keep='last') print (df2) A B C 1 1 2 y 2 3 4 z 3 3 5 x