Remove Python 2.7 and 3.5 support (#171)

* Remove also PyPy 2.x support.
* Specify the minimum supported Python version in
  pythoncapi_compat.h.

Author: vstinner

.github/workflows/build.yml

@@ -39,7 +39,6 @@ jobs:
           # - https://downloads.python.org/pypy/
           # - Only versions listed in this JSON are supported:
           #   https://downloads.python.org/pypy/versions.json
-          - "pypy2.7"
           - "pypy3.6"
           - "pypy3.7"
           - "pypy3.8"
@@ -49,7 +48,6 @@ jobs:
 
           # Old PyPy versions
           # See https://foss.heptapod.net/pypy/pypy/-/issues/3991
-          - "pypy2.7-v7.3.2"
           - "pypy3.6-v7.3.2"
           - "pypy3.7-v7.3.2"
 
@@ -117,21 +115,3 @@ jobs:
         run: python -VV
       - name: Run tests
         run: python runtests.py --current --verbose
-
-  test_python27:
-    # Get Python 2.7 from Ubuntu 22.04.
-    #
-    # Python 2.7 was removed from GHA setup-python in June 2023:
-    # https://github.com/actions/setup-python/issues/672
-    name: 'Test Python 2.7'
-    runs-on: ubuntu-22.04
-    steps:
-      - uses: actions/checkout@v4
-      - name: Install Python 2.7
-        run: |
-          sudo apt-get update
-          sudo apt-get -yq install python2.7 python2.7-dev
-      - name: Display the Python version
-        run: python2.7 -VV
-      - name: Run tests
-        run: python2.7 runtests.py --current --verbose

docs/api.rst

@@ -10,14 +10,10 @@ Supported Python versions:
 * Python 3.6 - 3.15
 * PyPy 2.7 and PyPy 3.6 - 3.10
 
-Python 2.7 and Python 3.5 are no longer officially supported since GitHub
-Actions doesn't support them anymore: only best effort support is provided.
-
 C++03 and C++11 are supported on Python 3.6 and newer.
 
 A C11 subset (without optional features) is required, like ``static inline``
-functions: see `PEP 7 <https://www.python.org/dev/peps/pep-0007/>`_. ISO C90
-is partially supported for Python 2.7.
+functions: see `PEP 7 <https://www.python.org/dev/peps/pep-0007/>`_.
 
 Some functions related to frame objects and ``PyThreadState`` are not available
 on PyPy.

docs/changelog.rst

@@ -1,6 +1,10 @@
 Changelog
 =========
 
+* 2026-09-07: Remove code to support Python 2.7, Python 3.5 and PyPy
+  for Python 2.7 ("pypy2").
+  Python 2.7 was no longer supported since August 2023.
+  Python 3.5 was no longer supported since October 2024.
 * 2026-02-12: Add functions:
 
   * ``PyUnstable_SetImmortal()``