Setuptools: Can sys.path be modified?

Scripting Issues
1

Recently I moved all my third-party modules to an directory external to my source directory, so I have something like this :

/ main.py
 ... /myapp/ ...
 .... /third-party/...

In my main.py I added the following line to add third-party to the paths where Python looks for modules to be imported :

[’/Users/ld/git/3D/cosmonium/build/macosx_10_6_x86_64/cosmonium.app/Contents/MacOS/…/Frameworks’]

sys.insert(0, 'third-party')

It probably isn’t the most elegant way, but it works :slight_smile:

However now when I build a binary version of the app, the app crashes:

    from panda3d.core import LPoint3d, LVector3d, LVector3, LQuaternion, LQuaterniond, LColor, BitMask32
  File "/usr/local/Cellar/python/3.7.5/Frameworks/Python.framework/Versions/3.7/lib/python3.7/importlib/_bootstrap.py", line 983, in _find_and_load
    return _find_and_load_unlocked(name, import_)
  File "/usr/local/Cellar/python/3.7.5/Frameworks/Python.framework/Versions/3.7/lib/python3.7/importlib/_bootstrap.py", line 967, in _find_and_load_unlocked
    module = _load_unlocked(spec)
  File "/usr/local/Cellar/python/3.7.5/Frameworks/Python.framework/Versions/3.7/lib/python3.7/importlib/_bootstrap.py", line 677, in _load_unlocked
    spec.loader.exec_module(module)
  File "/usr/local/Cellar/python/3.7.5/Frameworks/Python.framework/Versions/3.7/lib/python3.7/importlib/_bootstrap.py", line 819, in exec_module
    exec(code, module.__dict__)
  File "panda3d.core", line 1, in 
  File "/usr/local/Cellar/python/3.7.5/Frameworks/Python.framework/Versions/3.7/lib/python3.7/imp.py", line 342, in load_dynamic
    return _load(spec)
  File "/usr/local/Cellar/python/3.7.5/Frameworks/Python.framework/Versions/3.7/lib/python3.7/importlib/_bootstrap.py", line 696, in _load
    return _load_unlocked(spec)
  File "/usr/local/Cellar/python/3.7.5/Frameworks/Python.framework/Versions/3.7/lib/python3.7/importlib/_bootstrap.py", line 670, in _load_unlocked
    module = module_from_spec(spec)
  File "/usr/local/Cellar/python/3.7.5/Frameworks/Python.framework/Versions/3.7/lib/python3.7/importlib/_bootstrap.py", line 583, in module_from_spec
    module = spec.loader.create_module(spec)
  File "/usr/local/Cellar/python/3.7.5/Frameworks/Python.framework/Versions/3.7/lib/python3.7/importlib/_bootstrap_external.py", line 1043, in create_module
    _imp.create_dynamic, spec)
  File "/usr/local/Cellar/python/3.7.5/Frameworks/Python.framework/Versions/3.7/lib/python3.7/importlib/_bootstrap.py", line 219, in _call_with_frames_removed
    return f(*args, **kwds)
ImportError: dlopen(third-party/panda3d.core.so, 2): image not found

If I print the content of sys.path before and after my insert, I see that the path to the .so libraries is still there :

Before:

['/Users/ld/git/cosmonium/build/macosx_10_6_x86_64/cosmonium.app/Contents/MacOS/../Frameworks']

After

['third-party', '/Users/ld/git/cosmonium/build/macosx_10_6_x86_64/cosmonium.app/Contents/MacOS/../Frameworks']

So it seems that the importer does not tries all the paths but only check the first entry, (or raise an exception that is not catched in the loop over sys.path)

2

Apparently in FreezeTool.py, we use sys.path[0] to indicate something in particular when writing out the code for the panda3d.core module:

if self.platform.startswith("macosx") and not use_console:
    # We write the Frameworks directory to sys.path[0].
    code = 'import sys;del sys.modules["%s"];import sys,os,imp;imp.load_dynamic("%s",os.path.join(sys.path[0], "%s%s"))' % (moduleName, moduleName, moduleName, modext)

Try using sys.path.insert(1, path) instead.

Maybe we should instead be putting the Frameworks path elsewhere rather than expecting it to be at a certain location in sys.path (maybe an underscore-prefixed variable on sys, or so).

3

Thanks, it works fine, though now I need an even bigger comment before the code to explain why it is insert(1, …) :slight_smile: