CODEWITHSUNDEEP
pythonpandasdataframe
andrew fay
andrew fay

Reputation: 95

Find nlargest(2) of a column and split the result into separate columns

I want to group by two columns, find the nlargest(2) of a third column, and split those two values found from nlargest into two new columns. The code I have thus far:

dfworking.groupby(["STATE", "D"])['GENERAL PERCENT'].nlargest(2)

This finds me the two largest values, they print just find. How would I go from here and separate those 2 nlargest values into two separate columns?

Upvotes: 0

Views: 166

Answers (1)

cs95
cs95

Reputation: 402553

You can use groupby, agg, and .apply.

df

  col1  col2  col3
0     A     1   1.1
1     A     3   1.1
2     A     3   1.1
3     B     2   2.6
4     B     4   2.5
5     B     2   3.4
6     B     5   2.6
7     A     3   2.6
8     B     6   3.4
9     C     3   3.4
10    B     5   2.6
11    D     1   1.1
12    D     1   1.1
13    D     1   3.3

df.groupby(['col1', 'col2'])['col3']\
      .agg(lambda x: x.nlargest(2)).apply(pd.Series)

             0    1
col1 col2          
A    1     1.1  NaN
     3     2.6  1.1
B    2     3.4  2.6
     4     2.5  NaN
     5     2.6  2.6
     6     3.4  NaN
C    3     3.4  NaN
D    1     3.3  1.1

Upvotes: 1

Related Questions