Add "only_version" decorator to testing.

Author: domdfcoding

domdf_python_tools/testing.py

@@ -82,6 +82,7 @@
 		"count",
 		"min_version",
 		"max_version",
+		"only_version",
 		"not_windows",
 		"only_windows",
 		"not_pypy",
@@ -318,6 +319,31 @@ def max_version(
 	return pytest.mark.skipif(condition=sys.version_info[:3] > version_, reason=reason)
 
 
+def only_version(
+		version: Union[str, float, Tuple[int]],
+		reason: Optional[str] = None,
+		) -> MarkDecorator:
+	"""
+	Factory function to return a ``@pytest.mark.skipif`` decorator that will
+	skip a test if the current Python version not the required one.
+
+	:param version: The version number to compare to :py:data:`sys.version_info`.
+	:param reason: The reason to display when skipping.
+	:default reason: :file:`'Not needed on Python {<version>}.'`
+
+	:rtype:
+
+	.. versionadded:: 2.0.0
+	"""  # noqa D400
+
+	version_ = _make_version(version)
+
+	if reason is None:
+		reason = f"Not needed on Python {version_}."
+
+	return pytest.mark.skipif(condition=sys.version_info[:2] != version_[:2], reason=reason)
+
+
 def platform_boolean_factory(
 		condition: bool,
 		platform: str,

tests/test_testing.py

@@ -19,6 +19,7 @@
 		not_windows,
 		only_macos,
 		only_pypy,
+		only_version,
 		only_windows
 		)
 from domdf_python_tools.utils import strtobool
@@ -154,6 +155,22 @@ def test_generate_falsy():
 	assert list(testing.generate_falsy_values(ratio=0.3)) == ['0', "no", "False", False]
 
 
+@pytest.mark.parametrize(
+		"py_version",
+		[
+				pytest.param((3, 4), marks=only_version(3.4, "Success")),
+				pytest.param((3, 5), marks=only_version(3.5, "Success")),
+				pytest.param((3, 6), marks=only_version(3.6, "Success")),
+				pytest.param((3, 8), marks=only_version(3.8, "Success")),
+				pytest.param((3, 9), marks=only_version(3.9, "Success")),
+				pytest.param((3, 10), marks=only_version(3.10, "Success")),
+				]
+		)
+def test_only_version(py_version):
+	if sys.version_info[:2] != py_version:
+		assert False  # noqa: PT015
+
+
 @not_pypy("Success")
 def test_not_pypy():
 	if platform.python_implementation() == "PyPy":