Pandas rank by multiple columns

Question

I am trying to rank a pandas data frame based on two columns. I can rank it based on one column, but how can to rank it based on two columns? \'SaleCount\', then \'TotalReve

Answer 1

sort_values + GroupBy.ngroup

This will give the dense ranking.

Columns should be sorted in the desired order prior to the groupby. Specifying sort=False within the groupby then respects this sorting so that groups are labeled in the order they appear within the sorted DataFrame.

cols = ['SaleCount', 'TotalRevenue']
df['Rank'] = df.sort_values(cols, ascending=False).groupby(cols, sort=False).ngroup() + 1

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Output:

print(df.sort_values('Rank'))

   TotalRevenue        Date  SaleCount shops  Rank
1          9000  2016-12-02        100    S2     1
5          2000  2016-12-02        100    S8     2
3           750  2016-12-02         35    S5     3
2          1000  2016-12-02         30    S1     4
7           600  2016-12-02         30    S7     5
4           500  2016-12-02         20    S4     6
9           500  2016-12-02         20   S10     6
0           300  2016-12-02         10    S3     7
8            50  2016-12-02          2    S9     8
6             0  2016-12-02          0    S6     9