Pandas: how to transpose part of a dataframe

Question

I have the following dataframe:

   A  B   C param1 param2 param3
0  1  4 NaN   val1   val4   val7
1  2  5 NaN   val2   val5   val8
2  3  6 NaN   val3   val6   val9

Which I'd like to modify to get:

   A  B       C Values
0  1  4  param1   val1
1  1  4  param2   val4
2  1  4  param3   val7
3  2  5  param1   val2
4  2  5  param2   val5
5  2  5  param3   val8
6  3  6  param1   val3
7  3  6  param2   val6
8  3  6  param3   val9

How do I achieve this ?

`df.drop('C', axis=1).melt(id_vars=['A', 'B'], var_name='C', value_name='Values')` — Henry Ecker, Jul 08 '21 at 18:18
`df.drop('C', axis=1).set_index(['A', 'B']).stack().reset_index(name='Values').rename(columns={'level_2': 'C'})` — Henry Ecker, Jul 08 '21 at 18:21
FWIW I think [pandas convert some columns into rows](https://stackoverflow.com/q/28654047/15497888) would be a much more useful duplicate. — Henry Ecker, Jul 08 '21 at 18:21

score 0 · Answer 1 · answered Jul 08 '21 at 18:22

0

df.melt(id_vars = ['A','B'], value_vars = ['param1','param2', 'param3'])

You can check melt function and it can change the label for the id_vars and value_vars.

answered Jul 08 '21 at 18:22

Dan_Lee

87
6

Pandas: how to transpose part of a dataframe

1 Answers1