4 ways to put the version number into setup.py for your Python package

Assume that we’re developing a Python package pypkg with a directory structure like this:

pypkg
  |+++- pypkg/
  |       |+++- __init__.py
  |
  |+++- setup.py

And we have a statement __version__ = '5.5.6.6' in pypkg/__init__.py.

So the first way will be just import the module pypkg and then call pypkg.__version__ in the setup block in setup.py:

# In setup.py
import pypkg
... (skipped)
setup(
	version = pypkg.__version__
)

But sometimes we don’t want to import the module, so we can setup a regex to match version statement in __init__.py, and just search that file for a match:

# In setup.py
def get_version():
    VERSIONFILE = os.path.join('pypkg', '__init__.py')
    initfile_lines = open(VERSIONFILE, 'rt').readlines()
    VSRE = r"^__version__ = ['\"]([^'\"]*)['\"]"
    for line in initfile_lines:
        mo = re.search(VSRE, line, re.M)
        if mo:
            return mo.group(1)
    raise RuntimeError('Unable to find version string in %s.' % (VERSIONFILE,))
# ... (skipped)
setup(
	version = get_version()
)

If we want to get all metadatas (e.g. author) not just the version number, we can do it in the same way:

# In setup.py
module_file = open("pypkg/__init__.py").read()
metadata = dict(re.findall("__([a-z]+)__\s*=\s*'([^']+)'", module_file))
# ... (skipped)
setup(
	author = metadata['author']
	version = metadata['version']
)

Now we may want to separates the metadata from pypkg/__init__.py, say we put the statement __version__ = '5.5.6.6' into another file pypkg/version.py:

# In setup.py
exec(compile(open('pypkg/version.py').read(), 'pypkg/version.py', 'exec'))
# ... (skipped)
setup(
	version = __version__
)