Ah, I see. It looks like [Python 3 support](https://github.com/Toblerity/Shapely/issues/56) is being actively investigated, with [some contributions](https://github.com/mwtoews/shapely/commit/e6f6df2c4c5f8a63267e2c6b0e8cd10599d548a8) addressing exactly this use case. Perhaps we should help/wait-for the Shapely porting effort to conclude?