[Numpy-discussion] porting NumPy to Python 3

[Bruce Southey]

Charles R Harris wrote:
>
>
> On Wed, Feb 4, 2009 at 10:02 AM, James Watson <watson.jim at gmail.com 
> <mailto:watson.jim at gmail.com>> wrote:
>
>     Hi Ondrej,
>
>     To get 2to3 to run without warnings, the following files require
>     minor changes:
>     - numpy/distutils/fcompiler/intel.py
>     - numpy/distutils/misc_util.py
>     - numpy/distutils/command/build_src.py
>     - numpy/f2py/crackfortran.py
>     - numpy/lib/function_base.py
>     - numpy/linalg/lapack_lite/make_lite.py
>
>     There are also other (possibly many, still working on this) files that
>     require syntactic changes to run post 2to3.
>
>     Is there anywhere specific I should upload these changes?  Is this
>     list appropriate?  Is there a developer I can send these and future
>     patches to?
>
>
> Maybe we could add a python 3 milestone so folks could post tickets 
> for these sorts of things. For the time being you could just post to 
> the list here with the patches and something in the subject line that 
> identifies it as a patch for python 3. I think we could make any small 
> changes as long as they are compatible with python 2.4.
>
> Chuck
>
>
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>   
If you follow Guido's recommendation (at the bottom of 
http://docs.python.org/dev/3.0/whatsnew/3.0.html), then we should first 
be compatible with Python 2.6 (about the current stage) . Then 
compatible using Python 2.3 with the -3 flag (warn about Python 3.x 
incompatibilities) and fix warnings like:
 numpy/core/__init__.py:11: DeprecationWarning: the cPickle module has 
been removed in Python 3.0
(Of course you lose speed of cPickle if you blindly change it to use the 
old Pickle in Python 2.x)

Finally use the 2to3 tool to get a Python 3 version.

Bruce