How to tansfrom row data into column data format using pandas in python

Question

I have data in the below format.

Input

From    To  Zone 1  Zone 2  Zone 3  Zone 4  Zone 5
10.1    20  0.45    0.45    0.35    0.45    0.45
20.1    40  0.45    0.45    0.45    0.45    0.70
40.1    50  0.50    0.50    0.55    0.55    0.55
50.1    250 0.75    0.79    0.79    0.80    0.79

Desired Output

From    To  Kg  Attribute   Value
10.1    20  0.5 Zone 1          0.45
10.1    20  0.5 Zone 2          0.45
10.1    20  0.5 Zone 3          0.35
10.1    20  0.5 Zone 4          0.45
10.1    20  0.5 Zone 5          0.45
20.1    40  0.5 Zone 1          0.45
20.1    40  0.5 Zone 2          0.45
20.1    40  0.5 Zone 3          0.45
20.1    40  0.5 Zone 4          0.45
20.1    40  0.5 Zone 5          0.70

How can this be done in pandas python?

Answer 1

You can set From and To as index and use stack().

(
    df.set_index(['From', 'To']).stack().to_frame('Value')
    .rename_axis(['From', 'To', 'Attribute'])
    .assign(Kg=0.5)
    .reset_index()
)

    From    To  Attribute   Value   Kg
0   10.1    20  Zone1   0.45    0.5
1   10.1    20  Zone2   0.45    0.5
2   10.1    20  Zone3   0.35    0.5
3   10.1    20  Zone4   0.45    0.5
4   10.1    20  Zone5   0.45    0.5
5   20.1    40  Zone1   0.45    0.5
6   20.1    40  Zone2   0.45    0.5
7   20.1    40  Zone3   0.45    0.5
8   20.1    40  Zone4   0.45    0.5
9   20.1    40  Zone5   0.70    0.5
10  40.1    50  Zone1   0.50    0.5
11  40.1    50  Zone2   0.50    0.5
12  40.1    50  Zone3   0.55    0.5
13  40.1    50  Zone4   0.55    0.5
14  40.1    50  Zone5   0.55    0.5
15  50.1    250 Zone1   0.75    0.5
16  50.1    250 Zone2   0.79    0.5
17  50.1    250 Zone3   0.79    0.5
18  50.1    250 Zone4   0.80    0.5
19  50.1    250 Zone5   0.79    0.5