biopython/biopython — pull request #138 by bow (2012-12-20 04:30:21+00:00)
Title: Patch Bio.SeqUtils.GC_skew

Previously `GC_skew` would not work if there's any stretch of sequence containing only A and Ts. This patch updates the function so that instead of breaking, `None` is returned for that window.

Additionally, I've also removed some unused imports in `Bio.SeqUtils`.