[Biopython] Preparing to drop Python 3.3 support

[Peter Cock]

On Tue, Dec 15, 2015 at 3:50 AM, Mic <mictadlo at gmail.com> wrote:
> Hello,
> How about to add support for PYPY or does everything works under PYPY?
>
> Mic

Hi Mic,

We already test under PyPy - although I've not tried the new release v4 yet
(they jumped version numbers to avoid Python 2 vs 3 confusion).

As with Jython, none of our C code modules are available (nor NumPy),
but things seem to work fine. NumPy under PyPy is a special case as
there is a PyPy reimplementation of the Python parts of NumPy called
NumPyPy - that has improved a lot since I last tried using it with Biopython.

As with Jython, there are subtle differences with PyPy compared to the
classic C Python implementation - dictionary key order changes, and
object garbage collection timing varies. The later is most obvious with
things like ensuring handles are closed.

Peter