Check whether a python package has been installed in 'editable' (egg-link) mode or not?

Question

Is there any way to check whether a Python package has been installed normally (pip install / setup.py install) or in editable/egg-link mode (pip install -e / setup.py develop)?

I know I could check whether the path to the package contains site-packages which would most likely mean it's a "non-editable" install, but this feels extremely dirty and I would rather avoid this.

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The reason I'm trying to check this is that my application is checking for config files in various places, such as /etc/myapp.conf and ~/.myapp.conf. For developers I'd like to check in <pkgdir>/myapp.conf but since I show the list of possible locations in case no config was found, I really don't want to include the pkgdir option when the package has been installed to site-packages (since users should not create a config file in there).

Answer 1

pip contains code for this (it's used by pip freeze to prefix the line with -e). Since pip's API is not guaranteed to be stable, it's best to copy the code into the own application instead of importing it from pip:

def dist_is_editable(dist):
    """Is distribution an editable install?"""
    for path_item in sys.path:
        egg_link = os.path.join(path_item, dist.project_name + '.egg-link')
        if os.path.isfile(egg_link):
            return True
    return False

The code is MIT-licensed so it should be safe to copy&paste into pretty much any project.