问题
I need more perfomance running my neural network, so I thinked that building it with cython will be good idea. I am building my code like this:
from distutils.core import setup
from Cython.Build import cythonize
setup(
ext_modules = cythonize("my_code.pyx")
)
But will it build external python files that I use? Like pybrain, skimage and PIL in my case. If not, how to force cython to build them.
回答1:
No, external python files will not be cythonized and compiled unless you specifically add them to your setup.py as an extension. As far as I know there is no trivial way to do this.
This means that all calls to the external files will be handled in 'Python-space' and hence can not use the full potential of Cython. For example all calls to an external file will be type checked, which wastes a lot of time. You can see this if you cythonize a file using cython -a yourfile.pyx and take a look at the created C code. The more yellow there is the more pythony your code is.
You have the following options:
- Find libraries / packages that offer Cython or C-level access. Unfortunately chances are low that you will find good ones (or any at all) using Cython and building a wrapper for a C library is a lot of work. Note that packages that themselve are implemented in C (like numpy for example) already are reasonably fast. I do not know how this behaves with your packages in question. pybrains seems to be pure python from what I saw at first glance.
- Get the source code of the packages you want to use and compile them yourself with Cython. This might be an awful lot of work and not worth the time.
- Find the bottlenecks using a profiler like lineprofiler / kernprof (this should always be the first step when optimizing) and try to cythonize only the runtime bottlenecks.
I personally would go with option three, as options one and two both might require a lot of work on your side with questionable outcome.
来源：https://stackoverflow.com/questions/38248017/how-to-compile-my-python-code-in-cython-with-external-python-libs-like-pybrain