Add tox for Python testing

Author: cgoldberg

examples/python/requirements.txt

@@ -5,3 +5,4 @@ pytest-trio==0.8.0
 pytest-rerunfailures==15.0
 flake8==7.2.0
 requests==2.32.3
+tox==4.25.0

examples/python/tox.ini

@@ -0,0 +1,30 @@
+# Tox (https://tox.wiki/) is a tool for running tests in multiple
+# virtualenvs. This configuration file will run the test suite on all
+# supported python versions. To use it, run "tox" from this directory.
+#
+# For a specific environment, run: "tox -e <env>" (i.e.: "tox -e py313")
+#
+# This tox configuration will skip any Python interpreters that can't be found.
+# To manage multiple Python interpreters for covering all versions, you can use
+# pyenv: https://github.com/pyenv/pyenv
+
+
+[tox]
+env_list =
+    py39
+    py310
+    py311
+    py312
+    py313
+skip_missing_interpreters = True
+
+[testenv]
+description = run tests
+passenv = *
+deps =
+    -r requirements.txt
+commands =
+    # "-vv" means extra verbose
+    # "-r fEsxXp" means show extra test summary info as specified by:
+    #   (f)ailed, (E)rror, (s)kipped, (x)failed, (X)passed, (p)assed
+    pytest -vv -r fEsxXp {posargs:.}