Filter pandas Dataframe based on max values in a column

Question

I have a DataFrame with repeating values in the index. I would like to filter this dataset down to only show me one instance of each index by selecting the row within the in

Answer 1

You can perform a groupby on 'Product ID', then apply idxmax on 'Sales' column. This will create a series with the index of the highest values. We can then use the index values to index into the original dataframe using iloc

In [201]:

df.iloc[df.groupby('Product ID')['Sales'].agg(pd.Series.idxmax)]
Out[201]:
   Product_ID Store  Sales
1           1     B    200
3           2     A    400
5           3     A    200
8           4     C    500