add Cython version as a pip dependency

[drevicko]

When I tried to pip install pandas on a system with cython 0.15.1, it failed (I'm guessing that's not surprising). After pip installing cython (to 0.22), pandas installs fine. The error messages talked about missing lib.pxd and tslib.pxd files - to my untrained eye, Cython wasn't an obvious culprit!

My point is that, unless there's a good reason not to, the minimum cython version for compiling pandas should be a dependency in pip.

[shoyer]

Cython actually isn't an install requirement for pandas if you are using the pypi distribution (what you get from pip install pandas) -- it should install just fine without it. Frankly, I would think it should work even if you only have an older version of Cython installed... how did you install pandas?

[drevicko]

pip install pandas from within a virtualenv with system-site-packages turned on.

[shoyer]

Hmm. Looking through our setup.py file, it appears we attempt to build with Cython if it's installed without checking any minimum versions. That is indeed problematic -- the installation page mentions that cython 0.19.1 is required to build the dev version.

[jreback]

I suppose you could add this similarly to how numpy/pytz/dateutil are there. though the min version of cython is 0.19.1 is over 2 years old (and 0.15.1 is almost 4).

building with system installed libraries is not generally recommended, see the install instructions

[drevicko]

Yeah, it's an unusual case: a university server where I've not got sudo privelidges and Ubuntu 12.04 (with about 40 updates not installed! It's behind a firewall though..). Anyway, it's an easy fix and helpful for others in a similar situaion (:

[jreback]

@drevicko gr8 thanks!

[bashtage]

@drevicko You might want to consider Anaconda (esp Miniconda as a starting point)

[ajamian]

Attempting this as part of pycon sprints.