Python 3 not found on Mac OS

[jfilby]

When I try import a non-standard module I get an error. However when I import os it works fine.

When I run the following code:

let pysys = pyImport("sys")
echo pysys.version

It looks like nimpy is using Python 2 instead of Python 3. How can I point it to Python 3? I'm using a virtual environment to setup Python 3.

I found a similar issue: #46

[yglukhov]

You can use pyInitLibPath("/path/to/python.so") for that.

[jfilby]

Is pyInitLibPath() new? I installed Nimpy using nimble but when I try to compile I get:
Error: undeclared identifier: 'pyInitLibPath'

Also, do you know the actual name of the library? I don't have a python.so file on my system (Mac OS).

[jfilby]

It worked with the latest code, thanks, I just pointed pyInitLibPath to the python 3 binary in my virtual env.

[drewbitt]

@yglukhov why is this necessary for MacOS but not for windows? Code runs fine on Windows without specifying the path but doesn't on MacOS for me as well.

python -c 'import sys; print(sys.path)'
['', '/Users/drewbitt/.pyenv/versions/3.8.2/lib/python38.zip', '/Users/drewbitt/.pyenv/versions/3.8.2/lib/python3.8', '/Users/drewbitt/.pyenv/versions/3.8.2/lib/python3.8/lib-dynload', '/Users/drewbitt/.pyenv/versions/3.8.2/lib/python3.8/site-packages']

In nimpy:

['/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python27.zip', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-darwin', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac/lib-scriptpackages', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-tk', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-old', '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload', '/Library/Python/2.7/site-packages', '/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python', '/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/PyObjC', '/Users/drewbitt/Documents/Github/wn-reading-list-backend/src/util']

which is the system python

There is no libpython*.so*

[drewbitt]

It looks like you load the first libpython*dylib you find. Can we get the ability to specify what version we want then?

[drewbitt]

Actually, that wouldn't help here since it is completely not finding any python3 dylibs.

[singularperturbation]

If you're using pyenv on Mac OS, make sure that you have PYTHON_CONFIGURE_OPTS="--enable-framework" pyenv install <VERSION> to get it built with a dynamic library, otherwise I don't think that this will work (because it will only have a static library to load).

(found this from JuliaPy/PyCall.jl#122)

[timotheecour]

workaround: use find_libpython to find the libpython shared library reliably; see #171