On Fri, Sep 21, 2012 at 5:39 PM, Nathaniel Smith <n...@pobox.com> wrote: > On Fri, Sep 21, 2012 at 9:42 PM, Ralf Gommers <ralf.gomm...@gmail.com> wrote: >> Eh, just installing numpy with "python setup.py install" uses plain >> distutils, not setuptools. So there indeed isn't an entry in >> easy-install.pth. Which some consider a feature:) > > I don't think this is correct. To be clear on the technical issue: > what's going on is that when pip sees install_requires=["numpy"], it > needs to check whether you already have the distribution called > "numpy" installed. It turns out that in the wonderful world of python > packaging, "distributions" are not quite the same as "packages", so it > can't do this by searching PYTHONPATH for a "numpy" directory. What it > does is search PYTHONPATH for a file named > numpy-<version-number->.egg-info[1]. This isn't *quite* as dumb as it > seems, because in practice there really isn't a 1-to-1 mapping between > source distributions and installed packages, but it's... pretty dumb. > Anyway. The problem is that Ralf installed numpy by doing an in-place > build in his source tree, and then adding his source tree to his > PYTHONPATH. But, he didn't put a .egg-info on his PYTHONPATH, so pip > couldn't tell that numpy was installed, and did something dumb. > > So the question is, how do we get a .egg-info? For the specific case > Ralf ran into, I'm pretty sure the solution is just that if you're > clever enough to do an in-place build and add it to your PYTHONPATH, > you should be clever enough to also run 'python setupegg.py egg_info' > which will create a .egg-info to go with your in-place build and > everything will be fine. > > The question is whether there are any other situations where this can > break. I'm not aware of any. Contrary to what's claimed in the bit I > quoted above, I just ran a plain vanilla 'python setup.py install' on > numpy inside a virtualenv, and I ended up with a .egg-info installed. > I'm pretty sure plain old distutils installs .egg-infos these days > too. In that bug report Ralf says there's some problem with > virtualenvs, but I'm not sure what (I use virtualenvs extensively and > have never run into anything). Can anyone elaborate? > > [1] or several other variants, see some PEP or another for the tedious > details. > > -n > > P.S.: yeah the thing where pip decides to upgrade the world is REALLY > OBNOXIOUS. It also appears to be on the list to be fixed in the next > release or the next release+1, so I guess there's hope?: > https://github.com/pypa/pip/pull/571
In statsmodels we moved to the check that Ralf proposes, and no requires. When I'm easy_installing a package I always need to watch out when a package tries to upgrade numpy. I just had to hit Crtl-C several times when the requires of pandas tried to update my numpy version. Josef > _______________________________________________ > NumPy-Discussion mailing list > NumPy-Discussion@scipy.org > http://mail.scipy.org/mailman/listinfo/numpy-discussion _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
