chore: py312 compat; imp is gone, use importlib (#24)

* chore: py312 compat; imp is gone, use importlib

The long-deprecated `imp` module is gone in Python 3.12. Use the
`importlib` module to provide the same functionality.

* ci: drop py35, add py311

* add python 3.12 to the pipeline

* fix type in previous commit

* declare support for python 3.11 and 3.12. Remove 3.5

* Update setup.py

---------

Co-authored-by: Federico Caselli <CaselIT@users.noreply.github.com>
Co-authored-by: Vytautas Liuolia <vytautas.liuolia@gmail.com>

.github/workflows/tests.yaml

@@ -23,9 +23,6 @@ jobs:
         toxenv:
           - "pep8"
         include:
-          - python-version: "3.5"
-            os: ubuntu-20.04
-            toxenv: py35
           - python-version: "3.6"
             os: ubuntu-20.04
             toxenv: py36
@@ -41,6 +38,12 @@ jobs:
           - python-version: "3.10"
             os: ubuntu-20.04
             toxenv: py310
+          - python-version: "3.11"
+            os: ubuntu-20.04
+            toxenv: py311
+          - python-version: "3.12.0-alpha - 3.12"
+            os: ubuntu-20.04
+            toxenv: py312
           - python-version: pypy3
             os: ubuntu-20.04
             toxenv: pypy3

setup.py

@@ -1,12 +1,19 @@
-import imp
+import importlib.machinery
+import importlib.util
 import io
 from os import path
 
 from setuptools import find_packages, setup
 
-VERSION = imp.load_source('version', path.join('.', 'token_bucket', 'version.py'))
-VERSION = VERSION.__version__
+loader = importlib.machinery.SourceFileLoader(
+    'version', path.join('.', 'token_bucket', 'version.py')
+)
+spec = importlib.util.spec_from_loader(loader.name, loader)
+module = importlib.util.module_from_spec(spec)
+
+loader.exec_module(module)
 
+VERSION = module.__version__
 
 setup(
     name='token_bucket',
@@ -28,20 +35,21 @@
         'Programming Language :: Python',
         'Programming Language :: Python :: Implementation :: CPython',
         'Programming Language :: Python :: Implementation :: PyPy',
-        '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',
+        'Programming Language :: Python :: 3.11',
+        'Programming Language :: Python :: 3.12',
     ],
     keywords='web http https cloud rate limiting token bucket throttling',
     author='kgriffs',
     author_email='mail@kgriffs.com',
     url='https://github.com/falconry/token-bucket',
     license='Apache 2.0',
     packages=find_packages(exclude=['tests']),
-    python_requires='>=3.5',
+    python_requires='>=3.6',
     install_requires=[],
     setup_requires=['pytest-runner'],
     tests_require=['pytest'],