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

Another way would be to type-cast both the columns of interest to str and combine them by concatenating them. Convert these back to numerical values so that they could be differentiated based on their magnitude.

In method=dense, ranks of duplicated values would remain unchanged. (Here: 6)

Since you want to rank these in their descending order, specifying ascending=False in Series.rank() would let you achieve the desired result.

col1 = df["SaleCount"].astype(str) 
col2 = df["TotalRevenue"].astype(str)
df['Rank'] = (col1+col2).astype(int).rank(method='dense', ascending=False).astype(int)
df.sort_values('Rank')