creating multi index from data grouped by month in Pandas - pandas

Question

Consider this sample data:
Month Location Products Sales Profit
JAN 1 43 32 20
JAN 2 82 54 25
JAN 3 64 43 56
FEB 1 37 28 78
FEB 2 18 15 34
FEB 3 5 2 4
MAR 1 47 40 14
The multi-index transformation I am trying to achieve is this:
JAN FEB MAR
Location Products Sales Profit Products Sales Profit Products Sales Profit
1 43 32 29 37 28 78 47 40 14
2 82 54 25 18 15 34 null null null
3 64 43 56 5 2 4 null null null
I tried versions of this:
df.stack().to_frame().T
It put all the data into one row. So, that's not the goal.
I presume I am close in that it should be a stacking or unstacking, melting or unmelting, but my attempts have all resulted in data oatmeal at this point. Appreciate your time trying to solve this one.

Answer 1

You can use pivot with reorder_levels and sort_index():
df.pivot(index='Location',columns='Month').reorder_levels(order=[1,0],axis=1).sort_index(axis=1)
Month FEB JAN MAR
Products Profit Sales Products Profit Sales Products Profit Sales
Location
1 37.0 78.0 28.0 43.0 20.0 32.0 47.0 14.0 40.0
2 18.0 34.0 15.0 82.0 25.0 54.0 NaN NaN NaN
3 5.0 4.0 2.0 64.0 56.0 43.0 NaN NaN NaN
In case you are interested, this answer elaborates between swaplevel and reoder_levels.

Answer 2

Use pivot:
>>> df.pivot('Location', 'Month').swaplevel(axis=1).sort_index(axis=1)
Month FEB JAN MAR
Products Profit Sales Products Profit Sales Products Profit Sales
Location
1 37.0 78.0 28.0 43.0 20.0 32.0 47.0 14.0 40.0
2 18.0 34.0 15.0 82.0 25.0 54.0 NaN NaN NaN
3 5.0 4.0 2.0 64.0 56.0 43.0 NaN NaN NaN
To preserve order, you have to transform your Month column as CategoricalDtype before:
df['Month'] = df['Month'].astype(pd.CategoricalDtype(df['Month'].unique(), ordered=True))
out = df.pivot('Location', 'Month').swaplevel(axis=1).sort_index(axis=1)
print(out)
# Output:
Month JAN FEB MAR
Products Profit Sales Products Profit Sales Products Profit Sales
Location
1 43.0 20.0 32.0 37.0 78.0 28.0 47.0 14.0 40.0
2 82.0 25.0 54.0 18.0 34.0 15.0 NaN NaN NaN
3 64.0 56.0 43.0 5.0 4.0 2.0 NaN NaN NaN
Update 2
Try to force the order of level 2 columns:
df1 = df.set_index(['Month', 'Location'])
df1.columns = pd.CategoricalIndex(df1.columns, ordered=True)
df1 = df1.unstack('Month').swaplevel(axis=1).sort_index(axis=1)