tox -= CPython 3.5, 3.6, 3.7

Those py3 versions are long EOL now: https://devguide.python.org/versions/

Note that we still do support py2.7 .

/reviewed-by @jerome
/reviewed-on !24

setup.py

@@ -346,9 +346,6 @@ setup(
         Programming Language :: Python :: 2
         Programming Language :: Python :: 2.7
         Programming Language :: Python :: 3
-        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

 [tox]
 envlist =
-    {py27d,py27,py37,py38,py39d,py39,py310d,py310,py311d,py311,py312,pypy,pypy3}-{thread,gevent}
+    {py27d,py27,py38,py39d,py39,py310d,py310,py311d,py311,py312,pypy,pypy3}-{thread,gevent}
 
 
 # ThreadSanitizer
@@ -10,24 +10,23 @@ envlist =
 # (*) PyPy locks its GIL (see RPyGilAcquire) by manually doing atomic cmpxchg
 # and other games, which TSAN cannot see if PyPy itself was not compiled with
 # -fsanitize=thread.
-    {py27d,py27,py37,py38,py39d,py39,py310d,py310,py311d,py311,py312           }-{thread       }-tsan
+    {py27d,py27,py38,py39d,py39,py310d,py310,py311d,py311,py312           }-{thread       }-tsan
 # XXX py*-gevent-tsan would be nice to have, but at present TSAN is not
 # effective with gevent, because it does not understand greenlet "thread"
 # switching and so perceives the program as having only one thread where races
 # are impossible. Disabled to save time.
-#   {py27d,py27,py37,py38,py39d,py39,py310d,py310,py311d,py311,py312           }-{       gevent}-tsan
+#   {py27d,py27,py38,py39d,py39,py310d,py310,py311d,py311,py312           }-{       gevent}-tsan
 
 
 # AddressSanitizer
 
 # XXX asan does not work with gevent: https://github.com/python-greenlet/greenlet/issues/113
-    {py27d,py27,py37,py38,py39d,py39,py310d,py310,py311d,py311,py312,pypy,pypy3}-{thread       }-asan
+    {py27d,py27,py38,py39d,py39,py310d,py310,py311d,py311,py312,pypy,pypy3}-{thread       }-asan
 
 [testenv]
 basepython =
     py27d:  python2.7-dbg
     py27:   python2.7
-    py37:   python3.7
     py38:   python3.8
     py39d:  python3.9-dbg
     py39:   python3.9