How to split the column into two under same column name and having same values in Python?

Question

I am trying to split (internal split) a column so that there are two columns under the same column name and both those column should have the same values.

I am trying to implement the following in Python using Pandas library

Say My data-frame looks like this

        Column1  Column2
Row1       1        2
Row2       3        4 

Desired Output:

         Column1  Column2
 Row1     1 | 1    2 | 2
 Row2     3 | 3    4 | 4 

Answer 1

If we begin with your example:

df = pd.DataFrame({'Column1': [1, 3],
                   'Column2': [2,4]},
                  index = ['Row1', 'Row2'])

df

      Column1   Column2
Row1        1         2
Row2        3         4

1. Use pd.concat and interleave methods to make a duplicate of each column and ensure that each column's duplicate appears just to its right:

from toolz import interleave
df = pd.concat([df, df], axis=1)[list(interleave([df]))]

At this point, the dataframe looks like:

df

     Column1 Column1 Column2 Column2
Row1       1       1       2       2
Row2       3       3       4       4

2. Now change the dataframe's columns to a MultiIndex:

df.columns = pd.MultiIndex(levels=[['Column1', 'Column2'], ['A', 'B']],
           labels=[[0, 0, 1, 1], [0, 1, 0, 1]])

Which results in a dataframe that now appears like this:

df

        Column1   Column2
        A   B     A   B
Row1    1   1     2   2
Row2    3   3     4   4