Allow selection between pyzmq and pyzmq-static.

[matthewryanscott]

STATIC_DEPS=1 on the command line will turn on pyzmq-static dependency; otherwise, pyzmq itself is used.

I added this because it was easy to install a pre-built binary egg for pyzmq on Windows, but could not easily install pyzmq-static.

Note that I have not yet tested this. I'll have another, separate patch soon that makes the "zerorpc-client" script install correctly on Windows.

[bombela]

Is it possible to automatically install pyzmq-static when pyzmq is not found? I have no clue if that's something easy/doable with distutils...

[matthewryanscott]

I am not sure if there is something in distutils or setuptools that can do that.

One approach I can think of is to try an import at the top:

try:
    import zmq
except ImportError, e:
    zmq = None

Then build a list of dependencies, attaching pyzmq-static to the bottom as needed:

REQUIREMENTS = [
    'req1 >= 1.0, < 1.1',
    'req2, >= 1.2, < 1.3',
]
if zmq is None:
    REQUIREMENTS.append('pyzmq-static >= 2.1.7.1, < 2.2')

setup(
    # ...
    install_requires=REQUIREMENTS,
    # ...
)

[bombela]

what about simply detecting if we are on windows? then it select the non-static one?

import platform
platform.system()
'Windows'

At the time goes, we will know if it need to be handled in a different way for different OS/platform. What do you think?