将列转换为行 DataFrame

Question

I have the following DataFrame:

Name	A	B	C	D	E
BTU	2	3	0	9	7
BTP	1	2	7	9	0

And I want this:

Name	letter	Value
BTU	A	2
BTU	B	3
BTU	C	0
BTU	D	9
BTU	E	7
BTP	A	1
BTP	B	2
BTP	C	7
BTP	D	9
BTP	E	0

How can I do it?

Answer 1

You can do this with melt :

pd.melt(df, id_vars=['Name'], value_vars=['A', 'B', 'C', 'D', 'E'], var_name='letter', value_name='Value').sort_values(by='Name', ascending=False)

Result:

	Name	letter	Value
0	BTU	A	2
2	BTU	B	3
4	BTU	C	0
6	BTU	D	9
8	BTU	E	7
1	BTP	A	1
3	BTP	B	2
5	BTP	C	7
7	BTP	D	9
9	BTP	E	0