Issue #29: Switch to CalVer, require Python >= 3.6

NEWS.rst

@@ -1,6 +1,33 @@
 Release History
 ---------------
 
+21.6.0 (2021-06-TBD)
+^^^^^^^^^^^^^^^^^^^^^^^^
+
+* Switched to calendar based versioning rather than continuing with pre-1.0
+  semantic versioning (`#29 <https://github.com/jazzband/contextlib2/issues/29>`__)
+* Due to the inclusion of asynchronous features from Python 3.7+, the
+  minimum supported Python version is now Python 3.6
+  (`#29 <https://github.com/jazzband/contextlib2/issues/29>`__)
+* (WIP) Synchronised with the Python 3.10 version of contextlib, bringing the
+  following new features to Python 3.6+ (
+  `#12 <https://github.com/jazzband/contextlib2/issues/12>`__,
+  `#19 <https://github.com/jazzband/contextlib2/issues/19>`__,
+  `#27 <https://github.com/jazzband/contextlib2/issues/27>`__):
+
+  * ``asyncontextmanager`` (Python 3.7)
+  * ``aclosing`` (Python 3.10)
+  * ``AbstractAsyncContextManager`` (Python 3.7)
+  * ``AsyncContextDecorator`` (Python 3.10)
+  * ``AsyncExitStack`` (Python 3.7)
+  * async support in ``nullcontext`` (Python 3.10)
+
+* Updates to the default compatibility testing matrix:
+
+  * Added: CPython 3.9, CPython 3.10
+  * Dropped: CPython 2.7, CPython 3.5, PyPy2
+
+
 0.6.0.post1 (2019-10-10)
 ^^^^^^^^^^^^^^^^^^^^^^^^
 

VERSION.txt

@@ -1 +1 @@
-0.6.0.post1
+21.6.0

setup.py

@@ -7,7 +7,7 @@ except ImportError:
 setup(
     name='contextlib2',
     version=open('VERSION.txt').read().strip(),
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
+    python_requires='>=3.6',
     py_modules=['contextlib2'],
     license='PSF License',
     description='Backports and enhancements for the contextlib module',
@@ -19,13 +19,13 @@ setup(
         'Development Status :: 5 - Production/Stable',
         'License :: OSI Approved :: Python Software Foundation License',
         # These are the Python versions tested, it may work on others
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
+        # It definitely won't work on versions without native async support
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.4',
-        'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
+        'Programming Language :: Python :: 3.8',
+        'Programming Language :: Python :: 3.9',
+        'Programming Language :: Python :: 3.10',
     ],
 
 )

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py{27,35,36,37,py,py3}
+envlist = py{36,37,38,39,3_10,py3}
 skip_missing_interpreters = True
 
 [testenv]
@@ -9,15 +9,12 @@ commands =
     coverage xml
 deps =
     coverage
-    py27: unittest2
-    pypy: unittest2
 
 [gh-actions]
 python =
-    2.7: py27
-    3.5: py35
     3.6: py36
     3.7: py37
     3.8: py38
-    pypy2: pypy
+    3.9: py39
+    3.10: py3_10
     pypy3: pypy3