How to Tell Pyximport to Use the Cython --Cplus Option

How do you tell pyximport to use the cython --cplus option?

One way to make Cython create C++ files is to use a pyxbld file. For example, create foo.pyxbld containing the following:

def make_ext(modname, pyxfilename):
    from distutils.extension import Extension
    return Extension(name=modname,
                     sources=[pyxfilename],
                     language='c++')

How can I set Cython compiler flags when using pyximport?

You should use a .pyxbld file, see for example this question.
For a file named foo.pyx, you would make a foo.pyxbld file. The following would give extra optimization args:

def make_ext(modname, pyxfilename):
    from distutils.extension import Extension
    return Extension(name=modname,
                     sources=[pyxfilename],
                     extra_compile_args=['-O3', '-march=native'])

I think it might be possible to pass in extra setup options to pyximport.install if you jump through enough hoops (messing around with distribute) to get the setup_args in the form it likes, however in the pyximport module documentation it recommends using a .pyxbld file, and in the test code for pyximport only that method is tested, so if there is another way it should be considered unstable/untested and .pyxbld should be considered the proper way of doing this.

Compiling cython with gcc: No such file or directory from #include ios

<ios> is a c++-header. The error message shows that you try to compile a C++-code as C-code.

Per default, Cython will produce a file with extension *.c, which will be interpreted as C-code by the compiler later on.

Cython can also produce a file with the right file-extension for c++, i.e. *.cpp. And there are multiple ways to trigger this behavior:

adding # distutils: language = c++ at the beginning of the pyx-file.
adding language="c++" to the Extension definition in the setup.py-file.
call cython with option --cplus.
in IPython, calling %%cython magic with -+, i.e. %%cython -+.
for alternatives when building with pyximport, see this SO-question.

Actually, for cythonize there is no command line option to trigger c++-generation, thus the first options looks like the best way to go:

# distutils: language = c++

from spacy.structs cimport TokenC
print("loading")

The problem is that spacy/structs.pxd uses c++-constructs, for example vectors or anything else cimported from libcpp:

...
from libcpp.vector cimport vector
...

and thus also c++-libraries/headers are needed for the build.

Wrt. Anaconda Python 3.4 and Cython

import numpy is just a regular import. Unless you do cimport numpy Cython doesn't treat this specially (it doesn't import headers or other compile-time files), thus there's nothing special to include.

I very much doubt there is any special feature Anaconda is doing.

If you want to configure pyximport, you can make a pxybld file, such as when you want to support C++ with pyximport.

Error with Object mapper reading JSON from file

"firstName" != "firstname"

Check the case of your property.