I thought about plotting the result of a hierarchical clustering by using matplotlib.pyplot. Some nice example plots can be found e.g. at
https://joernhees.de/blog/2015/08/26/scipy-hierarchical-clustering-and-dendrogram-tutorial/ .
The distance matrix described as a list Z contains the clusters sorted by distance and therefore looks like self._data in hierarchical.py in this package. Have you ever thought about a function which could translate the object-oriented version in your code to the id-based version of SciPy and matplotlib.dendogram? If so, are you aware of any (hidden) problems? If not, would you accept a pull request providing such a visualization?