Add setuptools.get_version(path, field='__version__')

changelog.d/1679.change.rst

@@ -0,0 +1,3 @@
+Add ``setuptools.get_version(path, field='__version__')``. It extracts version
+info from lines like ``__version__ = '0.12'"`` in text files and Python
+sources without importing them.

setup.cfg

@@ -25,5 +25,3 @@ universal = 1
 [metadata]
 license_file = LICENSE
 
-[bumpversion:file:setup.py]
-

setup.py

@@ -89,7 +89,7 @@ def pypi_link(pkg_filename):
 
 setup_params = dict(
     name="setuptools",
-    version="40.8.0",
+    version=setuptools.get_version("setup.cfg", field="current_version"),
     description=(
         "Easily download, build, install, upgrade, and uninstall "
         "Python packages"

setuptools/__init__.py

@@ -27,7 +27,7 @@
 __all__ = [
     'setup', 'Distribution', 'Feature', 'Command', 'Extension', 'Require',
     'SetuptoolsDeprecationWarning',
-    'find_packages'
+    'find_packages', 'get_version'
 ]
 
 if PY3:
@@ -224,5 +224,25 @@ def findall(dir=os.curdir):
     return list(files)
 
 
+def get_version(path, field='__version__'):
+    """
+    Get version information from a text file. Version is extracted
+    from "key = value" format with key matched at the beginning of
+    a line and specified by `field` parameter. Returns string.
+    """
+    version_file = os.path.abspath(path)
+    # Using binary matching to avoid possible encoding problems
+    # when reading arbitrary text files
+    if type(field) is not bytes:
+        field = field.encode('utf-8')
+    for line in open(version_file, 'rb'):
+        if line.startswith(field):
+            # __version__ = "0.9"
+            # current_version = 4.8.0
+            _, value = line.split(b'=')
+            version = value.strip(b' \r\n\t\'\"').decode()
+            return version
+
+
 # Apply monkey patches
 monkey.patch_all()

setuptools/tests/test_get_version.py

@@ -0,0 +1,49 @@
+# -*- coding: utf-8 -*-
+
+"""Tests for setuptools.get_version()."""
+import os
+import codecs
+import shutil
+import tempfile
+
+import pytest
+
+from setuptools import __version__, get_version
+
+
+def test_own_version():
+    version = get_version('setup.cfg', field='current_version')
+
+    # `setup.py egg_info` which is run in bootstrap.py during package
+    # installation adds `.post` prefix to setuptools.__version__
+    # which becomes different from 'setup.cfg` file
+
+    # https://setuptools.readthedocs.io/en/latest/setuptools.html#egg-info
+
+    assert __version__.startswith(version + '.post')
+
+
+class TestFiles:
+    def setup_method(self, method):
+        self.tmpdir = tempfile.mkdtemp()
+
+    def teardown_method(self, method):
+        shutil.rmtree(self.tmpdir)
+
+    def test_python_file(self):
+        path = os.path.join(self.tmpdir, 'version.py')
+        with open(path, 'w') as fp:
+            fp.write('__version__ = "0.23beta"\n')
+
+        version = get_version(path)
+        assert version == '0.23beta'
+
+    def test_non_utf8_python_file(self):
+        path = os.path.join(self.tmpdir, 'russian.py')
+        with open(path, 'wb') as fp:
+            fp.write(u'# файл в русской кодировке\n\n'.encode('cp1251'))
+            fp.write(u'__version__ = "17.0"\n'.encode('cp1251'))
+
+        version = get_version(path)
+        assert version == '17.0'
+