How to Bootstrap numpy installation in setup.py

Question

I have a project which has a C extension which requires numpy. Ideally, I'd like whoever downloads my project to just be able to run python setup.py install or use one call to pip. The problem I have is that in my setup.py I need to import numpy to get the location of the headers, but I'd like numpy to be just a regular requirement in install_requires so that it will automatically be downloaded from the Python Package Index.

Here is a sample of what I'm trying to do:

from setuptools import setup, Extension import numpy as np  ext_modules = [Extension('vme', ['vme.c'], extra_link_args=['-lvme'],                          include_dirs=[np.get_include()])]  setup(name='vme',       version='0.1',       description='Module for communicating over VME with CAEN digitizers.',       ext_modules=ext_modules,       install_requires=['numpy','pyzmq', 'Sphinx']) 

Obviously, I can't import numpy at the top before it's installed. I've seen a setup_requires argument passed to setup() but can't find any documentation on what it is for.

Is this possible?

Answer 1

The following works at least with numpy1.8 and python{2.6,2.7,3.3}:

from setuptools import setup from setuptools.command.build_ext import build_ext as _build_ext  class build_ext(_build_ext):     def finalize_options(self):         _build_ext.finalize_options(self)         # Prevent numpy from thinking it is still in its setup process:         __builtins__.__NUMPY_SETUP__ = False         import numpy         self.include_dirs.append(numpy.get_include())  setup(     ...     cmdclass={'build_ext':build_ext},     setup_requires=['numpy'],     ... ) 

For a small explanation, see why it fails without the "hack", see this answer.

Note, that using setup_requires has a subtle downside: numpy will not only be compiled before building extensions, but also when doing python setup.py --help, for example. To avoid this, you could check for command line options, like suggested in https://github.com/scipy/scipy/blob/master/setup.py#L205, but on the other hand I don't really think it's worth the effort.

Answer 2

I found a very easy solution in [this post][1]:

Or you can stick to https://github.com/pypa/pip/issues/5761. Here you install cython and numpy using setuptools.dist before actual setup:

from setuptools import dist dist.Distribution().fetch_build_eggs(['Cython>=0.15.1', 'numpy>=1.10']) 

Works well for me!