A Compatible Way of Getting Package-Paths in Python

The Python community is always looking to improve things in the way of consistency, and that’s its best and worst feature because from time to time, one method isn’t finished before another method is begun.

For example, when it comes to something, like packaging, you may need to account for what you need in several different ways, such as identifying non-Python files in both the “package data” clauses of your setup attributes and listing them in a MANIFEST.in (one is considered only when building source distributions, and another is considered only when building binary distributions). However, in order to do this, you also have to embed the non-Python files within one of your actual source directories (the “package” directories), because the package-data files are made to belong to particular packages. We won’t even talk about the complexities of source and binary packages when packaging into a wheel. Such divergences are the topic of many entire series of articles.

With similar compatibility problems, in order to use one of the module loaders, for the purposes of reflection, the recommended package will vary depending on whether you’re running 2.x, 3.2/3.3, and 3.4 .

It’s a pain. For your convenience, this is such a flow, used to determine the path of the package:

_MODULE_NAME = 'module name'
_APP_PATH = None

# Works in 3.4

try:
    import importlib.util
    _ORIGIN = importlib.util.find_spec(_MODULE_NAME).origin
    _APP_PATH = os.path.abspath(os.path.dirname(_ORIGIN))
except:
    pass

# Works in 3.2

if _APP_PATH is None:
    try:
        import importlib
        _INITFILEPATH = importlib.find_loader(_MODULE_NAME).path
        _APP_PATH = os.path.abspath(os.path.dirname(_INITFILEPATH))
    except:
        pass

# Works in 2.x

if _APP_PATH is None:
    import imp
    _APP_PATH = imp.find_module(_MODULE_NAME)[1]
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