Distribution independent libpython path

Question

Under newer Ubuntu/Debian versions, libpython2.7.so is under /usr/lib/i386-linux-gnu/libpython2.7.so or /usr/lib/x86_64-linux-gnu/libpython2.7.so, etc. Earlier, they could be found in /usr/lib/libpython2.7.so, no matter the architecture. I haven't checked for other distributions. How do I find the path of libpython2.7.so with python?

`locate libpython` finds quite a lot more than just this single file, and I want to programmatically find the path and supply it to cmake. `ldd /usr/local/bin/python` gives `No such file or directory`, and `ldd /usr/bin/python` gives several library files, but `libpython2.7.so` is not one of them. — Psirus, Dec 14 '13 at 15:21
there is a package for this: https://pypi.org/project/find-libpython/ — TingQian LI, Jul 31 '23 at 07:36

score 11 · Answer 1 · answered Jun 09 '14 at 06:49

11

Using pkg-config is not the best option - it will not distinguish between different installations of Python, returning only the system installation. You are better off using the Python executable to discover the location of libpythonX.Y.so.

From inside Python:

   from distutils import sysconfig;
   print sysconfig.get_config_var("LIBDIR")

Or inside a Makefile:

   PYTHON_LIBDIR:=$(shell python -c 'from distutils import sysconfig; print sysconfig.get_config_var("LIBDIR")')

This will discover the location from whatever Python executable is first in $PATH and thus will work if there are multiple Python installations on the system.

Credit to Niall Fitzgerald for pointing this out.

answered Jun 09 '14 at 06:49

Chiggs

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9

It gives to me `/usr/lib`, while it's located in `/usr/lib/x86_64-linux-gnu` – Marco Sulla Sep 17 '16 at 15:10
1

didn't work for me. the same problem as Marco Sulla pointed out. – hamster on wheels Mar 09 '17 at 15:49
Same issue. :( Really wish there was a way to do this. – alecbz Sep 23 '17 at 22:36
1

Note that `LIBDIR` is not set in Windows (the question is about Linux, but someone might still try it). See https://stackoverflow.com/questions/47423246/get-pythons-lib-path for a portable way. – ivan_pozdeev Nov 22 '17 at 13:22

score 4 · Answer 2 · answered May 15 '18 at 19:24

Here is my solution which seems to work against system wide Debian and CentOS installation, anaconda on Debian, miniconda on OSX, virtualenv on Debian... but fails for system-wide python on OSX:

from distutils import sysconfig;
import os.path as op;
v = sysconfig.get_config_vars();
fpaths = [op.join(v[pv], v['LDLIBRARY']) for pv in ('LIBDIR', 'LIBPL')]; 
print(list(filter(op.exists, fpaths))[0])

and here it ran on my laptop:

$> for p in python python3 ~/anaconda-4.4.0-3.6/bin/python ~datalad/datalad-master/venvs/dev/bin/python ; do $p -c "from distutils import sysconfig; import os.path as op; v = sysconfig.get_config_vars(); fpaths = [op.join(v[pv], v['LDLIBRARY']) for pv in ('LIBDIR', 'LIBPL')]; print(list(filter(op.exists, fpaths))[0])"; done                                                                                                                               
/usr/lib/python2.7/config-x86_64-linux-gnu/libpython2.7.so                                                      
/usr/lib/python3.6/config-3.6m-x86_64-linux-gnu/libpython3.6m.so
/home/yoh/anaconda-4.4.0-3.6/lib/libpython3.6m.so
/usr/lib/python2.7/config-x86_64-linux-gnu/libpython2.7.so

P.S. I had no clue that it is such a problem... bad bad bad Python

score 0 · Answer 3 · answered Dec 15 '13 at 21:37

I'm assuming you're looking to link against this file. Python is usually installed with pkgconfig info to help compile against it. Specifically for the .so file, you should use pkg-config --libs python-2.7. From Python:

import subprocess
subprocess.check_output(["pkg-config", "--libs", "python-2.7"])

If the only flag shown is -lpython2.7, you might want to consider reading /etc/ld.so.conf to see default locations in which the linker looks for its libraries.

Distribution independent libpython path

3 Answers3

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