How to plot heatmap for the matrix for the pairwise comparison of sequence similarity in python?

Question

[ramsha]

I am working on sequence alignment and I want to show the percentage of difference among all the pairs. I got a pairwise comparison table in CSV format from MEGA in the following format.

a
b   1
c   2   5
d   1   8   7
e   3   9   6   6

How to use this type of distance matrix file for generating heatmaps in python.