Python Pandas - Only showing rows in DF for the MAX values of a column

问题

searched for this, but cannot find an answer.

Say I have a dataframe (apologies for formatting):

a Dave $400
a Dave $400
a Dave $400
b Fred $220
c James $150
c James $150
d Harry $50

And I want to filter the dataframe so it only shows the rows where the third column is the MAXIMUM value, could someone point me in the right direction?

i.e. it would only show Dave's rows

All I can find is ways of showing the rows where its the maximum value for each separate index (the indexes being A, B, C etc)

Thank you in advance

回答1:

This should work:

>>> df
       0  money
a   Dave    400
a   Dave    400
a   Dave    400
b   Fred    220
c  James    150
c  James    150
d  Harry     50

>>> df[df['money'] == df['money'].max()]
      0  money
a  Dave    400
a  Dave    400
a  Dave    400

回答2:

If your index is unique and you are OK with returning one row (in the case of multiple rows having the same max value) then you can use the idxmax method.

df.loc[df['money'].idxmax()]

And if you want to add some flare you can highlight the max value in each column with:

df.loc[df['money'].idxmax()].style.highlight_max()

来源：https://stackoverflow.com/questions/40959626/python-pandas-only-showing-rows-in-df-for-the-max-values-of-a-column