Standard Way to Embed Version into Python Package

Standard way to embed version into Python package?

Not directly an answer to your question, but you should consider naming it __version__, not version.

This is almost a quasi-standard. Many modules in the standard library use __version__, and this is also used in lots of 3rd-party modules, so it's the quasi-standard.

Usually, __version__ is a string, but sometimes it's also a float or tuple.

As mentioned by S.Lott (Thank you!), PEP 8 says it explicitly:

Module Level Dunder Names

Module level "dunders" (i.e. names with two leading and two trailing
underscores) such as __all__, __author__, __version__, etc.
should be placed after the module docstring but before any import
statements except from __future__ imports.

You should also make sure that the version number conforms to the format described in PEP 440 (PEP 386 a previous version of this standard).

How to have the python program version only in setup.cfg for runtime and packaging?

Two options I can think of – I'd go with the first.

1. Use setup.cfg's attr: support to read the version from the source

setup.cfg

[metadata]
version = attr:my_app.__version__

my_app/init.py

# ...
__version__ = '0.1.3'

2. Use importlib.metadata to read the version from the installation metadata

(New in Python 3.8, has backports for older Pythons)

from importlib.metadata import version

my_version = version('my_app')  

What is the correct way to share package version with setup.py and the package?

Set the version in setup.py only, and read your own version with pkg_resources, effectively querying the setuptools metadata:

file: setup.py

setup(
    name='foobar',
    version='1.0.0',
    # other attributes
)

file: __init__.py

from pkg_resources import get_distribution

__version__ = get_distribution('foobar').version

To make this work in all cases, where you could end up running this without having installed it, test for DistributionNotFound and the distribution location:

from pkg_resources import get_distribution, DistributionNotFound
import os.path

try:
    _dist = get_distribution('foobar')
    # Normalize case for Windows systems
    dist_loc = os.path.normcase(_dist.location)
    here = os.path.normcase(__file__)
    if not here.startswith(os.path.join(dist_loc, 'foobar')):
        # not installed, but there is another version that *is*
        raise DistributionNotFound
except DistributionNotFound:
    __version__ = 'Please install this project with setup.py'
else:
    __version__ = _dist.version

How can I get the version defined in setup.py (setuptools) in my package?

Interrogate version string of already-installed distribution

To retrieve the version from inside your package at runtime (what your question appears to actually be asking), you can use:

import pkg_resources  # part of setuptools
version = pkg_resources.require("MyProject")[0].version

Store version string for use during install

If you want to go the other way 'round (which appears to be what other answer authors here appear to have thought you were asking), put the version string in a separate file and read that file's contents in setup.py.

You could make a version.py in your package with a __version__ line, then read it from setup.py using execfile('mypackage/version.py'), so that it sets __version__ in the setup.py namespace.

Warning about race condition during install

By the way, DO NOT import your package from your setup.py as suggested in another answer here: it will seem to work for you (because you already have your package's dependencies installed), but it will wreak havoc upon new users of your package, as they will not be able to install your package without manually installing the dependencies first.

How do I get a python module's version number through code?

Generalized answer from Matt's, do a dir(YOURMODULE) and look for __version__, VERSION, or version. Most modules like __version__ but I think numpy uses version.version

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