Add compatibility shims for working with cpython fixtures.

Author: jaraco

jaraco/test/cpython.py

@@ -0,0 +1,35 @@
+"""
+Compatibility shims for getting stuff from test.support across
+Python versions (for compatibility with Python 3.9 and earlier).
+
+>>> os_helper = try_import('os_helper') or from_test_support('temp_dir')
+>>> os_helper.temp_dir
+<function temp_dir at ...>
+"""
+
+import importlib
+import types
+
+from jaraco.context import suppress
+from jaraco.collections import Projection
+
+
+def from_test_support(*names):
+    """
+    Return a SimpleNamespace of names from test.support.
+
+    >>> support = from_test_support('swap_item')
+    >>> support.swap_item
+    <function swap_item at ...>
+    """
+    import test.support
+
+    return types.SimpleNamespace(**Projection(names, vars(test.support)))
+
+
+@suppress(ImportError)
+def try_import(name):
+    """
+    Attempt to import a submodule of test.support; return None if missing.
+    """
+    return importlib.import_module(f'test.support.{name}')

setup.cfg

@@ -19,6 +19,7 @@ python_requires = >=3.8
 install_requires =
 	jaraco.functools
 	jaraco.context
+	jaraco.collections
 
 [options.extras_require]
 testing =