Lab41/igraph — pull request #2 by ostrowr (2014-06-19 23:37:31+00:00)
Title: Python: optimal_count now returns a value after calculation.

Previously, optimal_count returned `None` when it had not previously been calculated, but `self._optimal_count` when it had already been set. This causes `VertexDendrogram.as_clustering()` to fail when a optimal_count has not been called and no hint has been provided .