Re: [matplotlib-devel] MEP11: Attempting to deal with the Python library dependency issue

[Erik B. <eri...@gm...>]

On Wed, Oct 3, 2012 at 9:10 PM, Michael Droettboom <md...@st...> wrote:
> On 10/03/2012 05:26 PM, Erik Bray wrote:
>> On 10/03/2012 12:20 PM, Michael Droettboom wrote:
>>> I invite comments for a new MEP about improving the situation with
>>> respect to our bundling of third-party Python dependencies.
>>>
>>> In particular, I'd love feedback from the various stakeholders -- those
>>> producing binary installers and packages for the various platforms.
>>>
>>> https://github.com/matplotlib/matplotlib/wiki/MEP11
>>>
>>> Mike
>>
>> +1 Let me know if you need/want any help with any distribute or pip
>> intricacies.
>>
>> As for Windows, I need to double check, but I believe bdist_wininst
>> installers generated by setuptools/distribute do support installing
>> dependencies from PyPI.
>>
>> Regarding Numpy: I'm not sure, does Matplotlib require Numpy at build
>> time?  I'm guessing probably yes, but if not it can also be installed
>> by easy_install or pip.  IIRC easy_install will install one of the
>> pre-built binary eggs.  pip only installs/builds from source which can
>> be problematic sometimes. Though I fixed Numpy a while back to be
>> installable by pip so it *does* work so long as Numpy can be built on
>> your system.
>
> Numpy is required at build time (matplotlib C++ extensions need to
> include Numpy's headers), but I had assumed if it was a requirement, it
> would get installed first and then we'd be ok to proceed.  Is that not
> how pip works?
>
> Mike

Yes/no.  Pip does install dependencies first, but they aren't
available at run-time of the setup.py of the dependent
package--unfortunate but mostly true.  I've been meaning to see if I
can fix that.  And easy_install of course is flawed in that it
installs dependencies afterwards. easy_install does support
setup_requires for downloading and adding packages to the path when
running setup.py, but this does *not* work with Numpy.

So as you wrote in the MEP, Numpy will simply have to be installed
separately, I think, if the C++ modules require the Numpy headers.

Erik