bonanza bonanza - 2 months ago 19
Python Question

Sphinx matlab documentation error: missing module 'std'

I'm trying to document my MATLAB classes using sphinx. But whenever I want to run

make html
I get the following error:

% make html
sphinx-build -b html -d _build/doctrees . _build/html
Running Sphinx v1.4.6

Extension error:
Could not import extension sphinxcontrib.matlab (exception: No module named 'std')
make: *** [Makefile:53: html] Error 1


I'm on ArchLinux and tried the following installation ways, but all result in the same problem:

Try 1:

yaourt -S python-sphinx # (was already installed by default, just to show that the package came from arch repo)
sudo pip install -U sphinxcontrib-matlabdomain


Try 2:

yaourt -R python-sphinx # (I also removed all dependencies)
sudo pip -U install sphinx
sudo pip -U install -U sphinxcontrib-matlabdomain


In neither of the cases it worked (always the error from above). In each try I also verified that the
std
module is there via

# ll /usr/lib/python3.5/site-packages/sphinxcontrib*
-rw-r--r-- 1 root root 326 Sep 28 11:02 /usr/lib/python3.5/site-packages/sphinxcontrib_blockdiag-1.5.5-py2.7-nspkg.pth
-rw-r--r-- 1 root root 326 Sep 28 11:00 /usr/lib/python3.5/site-packages/sphinxcontrib_matlabdomain-0.2.7-py3.5-nspkg.pth

/usr/lib/python3.5/site-packages/sphinxcontrib:
total 152
-rw-r--r-- 1 root root 11457 Sep 28 11:02 blockdiag.py
-rw-r--r-- 1 root root 37815 Jun 20 2015 mat_documenters.py
-rw-r--r-- 1 root root 27529 Oct 7 2014 matlab.py
-rw-r--r-- 1 root root 46088 Jun 20 2015 mat_types.py
drwxr-xr-x 1 root root 126 Sep 28 11:03 __pycache__
-rw-r--r-- 1 root root 22278 Feb 7 2014 std.py

/usr/lib/python3.5/site-packages/sphinxcontrib_blockdiag-1.5.5.dist-info:
total 32
-rw-r--r-- 1 root root 1033 Sep 28 11:02 DESCRIPTION.rst
-rw-r--r-- 1 root root 4 Sep 28 11:03 INSTALLER
-rw-r--r-- 1 root root 2127 Sep 28 11:02 METADATA
-rw-r--r-- 1 root root 1193 Sep 28 11:02 metadata.json
-rw-r--r-- 1 root root 14 Sep 28 11:02 namespace_packages.txt
-rw-r--r-- 1 root root 1054 Sep 28 11:03 RECORD
-rw-r--r-- 1 root root 14 Sep 28 11:02 top_level.txt
-rw-r--r-- 1 root root 110 Sep 28 11:02 WHEEL

/usr/lib/python3.5/site-packages/sphinxcontrib_matlabdomain-0.2.7-py3.5.egg-info:
total 40
-rw-r--r-- 1 root root 1 Sep 28 11:00 dependency_links.txt
-rw-r--r-- 1 root root 487 Sep 28 11:00 installed-files.txt
-rw-r--r-- 1 root root 14 Sep 28 11:00 namespace_packages.txt
-rw-r--r-- 1 root root 1 Jun 20 2015 not-zip-safe
-rw-r--r-- 1 root root 8547 Sep 28 11:00 PKG-INFO
-rw-r--r-- 1 root root 28 Sep 28 11:00 requires.txt
-rw-r--r-- 1 root root 549 Sep 28 11:00 SOURCES.txt
-rw-r--r-- 1 root root 14 Sep 28 11:00 top_level.txt


P.S.: my default python has version 3.5.2

Edit 1:

% head $(which sphinx-build)
#!/usr/bin/python

# -*- coding: utf-8 -*-
import re
import sys

from sphinx import main

if __name__ == '__main__':
sys.argv[0] = re.sub(r'(-script\.pyw|\.exe)?$', '', sys.argv[0])
% which sphinx-build
/usr/bin/sphinx-build
% sphinx-build --version
Sphinx (sphinx-build) 1.4.6
% python --version
Python 3.5.2
% /usr/bin/python --version
Python 3.5.2

Answer

The extensions in the sphinx-contrib repository seem to be meant for Python 2. The import rules have changed in Python 3, therefore such errors can occur when Python 3 code is run with a Python 2 interpreter.

The solution is to install Sphinx and all its dependencies for Python 2. Your distribution might have python2-sphinx. On Fedora and Ubuntu the packages python-* are always Python 2 or both, python3-* is the Python 3 package.

On Arch Linux I know that python is symlinked to python3. So there might be additional python2-* packages. Install pip2 (because pip is likely to be pip3 on Arch Linux) and use that to install Sphinx.

You can find out which interpreter is called by running head -n 1 $(which sphinx-build) and then check the path.

  • /usr/bin/python: That is Python 2 on Ubuntu or Fedora, Python 3 on Arch Linux
  • /usr/bin/python3: Definitely Python 3
  • /usr/bin/python2: Definitely Python 2
  • /usr/bin/env python: Similar to the others.

Otherwise one could do a print of the Python version inside of the conf.py such that it is printed explicitly.