Replace column in Pandas dataframe with the mean of that column

Question

I have a dataframe:

df = pd.DataFrame([[1, 2], [1, 3], [4, 6]], columns=['A', 'B'])

   A  B
0  1  2
1  1  3
2  4  6

I want to return a dataframe of the same size containing the mean of each column:

   A      B
0  2  3.666
1  2  3.666
2  2  3.666

Is there a simple way of doing this?

Answer 1

You can only provide one single line at DataFrame creation time:

pd.DataFrame(data = [df.mean()], index = df.index)

It gives:

     A         B
0  2.0  3.666667
1  2.0  3.666667
2  2.0  3.666667