Getting Python package distribution version from within a package

Question

You can get the version of a python distribution using

import pkg_resources
pkg_resources.get_distribution("distro").version

This is great if you know the distribution name, however I need to dynamically figure out my distribution name at runtime.

# Common framework base app class, extended by each app
class App(object):
    def get_app_version(self) -> str:
        package_name = self.__class__.__module__.split('.')[0]
        try:
            return pkg_resources.get_distribution(package_name).version
        except Exception:
            return "development"

This works for cases where the app's package name is the same as the distribution name (e.g. requests). However this fails once they don't match (e.g. my-app containing package my_app).

So what I need is a mapping between distributions and their packages, which I'm sure must exist somewhere since pip seems to know what to delete when you call uninstall:

$ pip uninstall requests
Uninstalling requests-2.21.0:
  Would remove:
    /home/user/.virtualenvs/app/lib/python3.6/site-packages/requests-2.21.0.dist-info/*
    /home/user/.virtualenvs/app/lib/python3.6/site-packages/requests/*

How do I programatically access this mapping?

Answer 1

If you're looking for a solution that works both from your development—not installed, or just locally called—version, and an installed version, then try this solution.

Imports:

import ast
import csv
import inspect
from os import listdir, path

import pkg_resources

Utility function:

def get_first_setup_py(cur_dir):
    if 'setup.py' in listdir(cur_dir):
        return path.join(cur_dir, 'setup.py')
    prev_dir = cur_dir
    cur_dir = path.realpath(path.dirname(cur_dir))
    if prev_dir == cur_dir:
        raise StopIteration()
    return get_first_setup_py(cur_dir)

Now using Python's ast library:

def parse_package_name_from_setup_py(setup_py_file_name):
    with open(setup_py_file_name, 'rt') as f:
        parsed_setup_py = ast.parse(f.read(), 'setup.py')

    # Assumes you have an `if __name__ == '__main__':`, and that it's at the end:
    main_body = next(sym for sym in parsed_setup_py.body[::-1]
                     if isinstance(sym, ast.If)).body

    setup_call = next(sym.value
                      for sym in main_body[::-1]
                      if isinstance(sym, ast.Expr) and
                      isinstance(sym.value, ast.Call) and
                      sym.value.func.id in frozenset(('setup',
                                                      'distutils.core.setup',
                                                      'setuptools.setup')))

    package_version = next(keyword
                           for keyword in setup_call.keywords
                           if keyword.arg == 'version'
                           and isinstance(keyword.value, ast.Name))

    # Return the raw string if it is one
    if isinstance(package_version.value, ast.Str):
        return package_version.s

    # Otherwise it's a variable at the top of the `if __name__ == '__main__'` block
    elif isinstance(package_version.value, ast.Name):
        return next(sym.value.s
                    for sym in main_body
                    if isinstance(sym, ast.Assign)
                    and isinstance(sym.value, ast.Str)
                    and any(target.id == package_version.value.id
                            for target in sym.targets)
                    )

    else:
        raise NotImplemented('Package version extraction only built for raw strings and '
                             'variables in the same function that setup() is called')

Finally replace the function in @Gricey's answer by changing return "development" to:

return parse_package_name_from_setup_py(get_first_setup_py(path.dirname(__file__)))

Taken from my answer https://stackoverflow.com/a/60352386

Answer 2

I believe the project's name should be hard-coded if possible. If not then some function like the following could help figuring out the metadata for the installed distribution containing the current file (__file__):

import pathlib
import importlib_metadata

def get_project_distribution():
    for dist in importlib_metadata.distributions():
        try:
            relative = pathlib.Path(__file__).relative_to(dist.locate_file(''))
        except ValueError:
            pass
        else:
            if relative in dist.files:
                return dist
    return None

project_distribution = get_project_distribution()
if project_distribution:
    project_name = project_distribution.metadata['Name']
    version = project_distribution.metadata['Version']

---

Update (February 2021):

Looks like this could become easier thanks to the newly added packages_distributions() function in importlib_metadata:

• https://importlib-metadata.readthedocs.io/en/stable/using.html#package-distributions
• https://github.com/python/importlib_metadata/pull/287/files