Tornado warning only if exists continued (#22)

* Warn about MEMOIZE_FORCE_ASYNCIO only if tornado exists

If tornado _does not_ exist, forcing asyncio is a noop, consistent with normal operation, and does not deserve a warning.

* Fixed redundant waring if `tornado` is not available to be used (silenced) - version and changelog

* Fixed GitHub Actions build (python 3.5 & 3.6 no longer available).


---------

Co-authored-by: Charles Duffy <[email protected]>
Co-authored-by: Michał Żmuda <[email protected]>

Author: zmumi

.github/workflows/tox-tests.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python: ['3.5', '3.6', '3.7', '3.8', '3.9', '3.10', '3.11.0-alpha - 3.11']
+        python: ['3.7', '3.8', '3.9', '3.10', '3.11']
 
     steps:
       - uses: actions/checkout@v2

CHANGELOG.rst

@@ -1,3 +1,9 @@
+1.1.4
+-----
+
+* Fixed redundant waring if `tornado` is not available to be used (silenced).
+* Fixed GitHub Actions build (python 3.5 & 3.6 no longer available).
+
 1.1.3
 -----
 

memoize/coerced.py

@@ -3,14 +3,15 @@
 """
 
 import datetime
+import importlib.util
 import logging
 
 from memoize.memoize_configuration import force_asyncio
 
 logger = logging.getLogger('memoize')
 try:
-    if force_asyncio:
-        logger.warning('Forcefully omitting tornado availability check & switching to asyncio')
+    if force_asyncio and importlib.util.find_spec('tornado'):
+        logger.warning('Forcefully switching to asyncio even though tornado exists')
         raise ImportError()
 
     from tornado.ioloop import IOLoop

setup.py

@@ -14,7 +14,7 @@ def prepare_description():
 
 setup(
     name='py-memoize',
-    version='1.1.3',
+    version='1.1.4',
     author='Michal Zmuda',
     author_email='[email protected]',
     url='https://github.com/DreamLab/memoize',
@@ -37,8 +37,6 @@ def prepare_description():
         'Topic :: Software Development :: Libraries',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3 :: Only',
-        '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',

tox.ini

@@ -3,7 +3,7 @@ skipdist   = True
 
 # py-{asyncio,tornado} are added for GitHub Actions (where we have only one interpreter at the time)
 # py{35,36,37,38,39}-{asyncio,tornado} are added for development purposes (where one has multiple interpreters)
-envlist    = py-{asyncio,tornado},py{35,36,37,38,39,310,311}-{asyncio,tornado},coverage-py310,mypy-py310
+envlist    = py-{asyncio,tornado},py{37,38,39,310,311}-{asyncio,tornado},coverage-py310,mypy-py310
 
 [testenv]
 setenv        =