Add interpreter_version()

docs/tags.rst

@@ -106,6 +106,13 @@ Reference
     This typically acts as the prefix to the :attr:`~Tag.interpreter` tag.
 
 
+.. function:: interpreter_version(*, warn=False)
+
+    Returns the running interpreter's version.
+
+    This typically acts as the suffix to the :attr:`~Tag.interpreter` tag.
+
+
 .. function:: mac_platforms(version=None, arch=None)
 
     Yields the :attr:`~Tag.platform` tags for macOS.

packaging/tags.py

@@ -256,14 +256,6 @@ def _generic_abi():
         yield _normalize_string(abi)
 
 
-def _generic_interpreter(warn=False):
-    # type: (bool) -> str
-    version = _get_config_var("py_version_nodot", warn)
-    if not version:
-        version = "".join(map(str, sys.version_info[:2]))
-    return "{name}{version}".format(name=interpreter_name(), version=version)
-
-
 def generic_tags(
     interpreter=None,  # type: Optional[str]
     abis=None,  # type: Optional[Iterable[str]]
@@ -281,7 +273,9 @@ def generic_tags(
     """
     warn = _warn_keyword_parameter("generic_tags", kwargs)
     if not interpreter:
-        interpreter = _generic_interpreter(warn=warn)
+        interp_name = interpreter_name()
+        interp_version = interpreter_version(warn=warn)
+        interpreter = "".join([interp_name, interp_version])
     if abis is None:
         abis = _generic_abi()
     platforms = list(platforms or _platform_tags())
@@ -552,6 +546,9 @@ def _platform_tags():
 
 def interpreter_name():
     # type: () -> str
+    """
+    Returns the name of the running interpreter.
+    """
     try:
         name = sys.implementation.name  # type: ignore
     except AttributeError:  # pragma: no cover
@@ -560,6 +557,18 @@ def interpreter_name():
     return INTERPRETER_SHORT_NAMES.get(name) or name
 
 
+def interpreter_version(**kwargs):
+    # type: (bool) -> str
+    """
+    Returns the version of the running interpreter.
+    """
+    warn = _warn_keyword_parameter("interpreter_version", kwargs)
+    version = _get_config_var("py_version_nodot", warn=warn)
+    if not version:
+        version = "".join(map(str, sys.version_info[:2]))
+    return version
+
+
 def sys_tags(**kwargs):
     # type: (bool) -> Iterator[Tag]
     """

tests/test_tags.py

@@ -155,6 +155,45 @@ def test_multi_platform(self):
         assert given == expected
 
 
+class TestInterpreterName:
+    def test_sys_implementation_name(self, monkeypatch):
+        monkeypatch.setattr(sys.implementation, "name", "sillywalk")
+        assert tags.interpreter_name() == "sillywalk"
+
+    def test_platform(self, monkeypatch):
+        monkeypatch.delattr(sys.implementation, "name")
+        name = "SillyWalk"
+        monkeypatch.setattr(platform, "python_implementation", lambda: name)
+        assert tags.interpreter_name() == name.lower()
+
+    def test_interpreter_short_names(self, monkeypatch):
+        monkeypatch.setattr(sys.implementation, "name", "cpython")
+        assert tags.interpreter_name() == "cp"
+
+
+class TestInterpreterVersion:
+    def test_warn(self, monkeypatch):
+        called_with_warn = False
+
+        def get_config_var(var, warn):
+            nonlocal called_with_warn
+            called_with_warn = warn
+            return "38"
+
+        monkeypatch.setattr(tags, "_get_config_var", get_config_var)
+        tags.interpreter_version(warn=True)
+        assert called_with_warn
+
+    def test_python_version_nodot(self, monkeypatch):
+        monkeypatch.setattr(tags, "_get_config_var", lambda var, warn: "NN")
+        assert tags.interpreter_version() == "NN"
+
+    def test_sys_version_info(self, monkeypatch):
+        monkeypatch.setattr(tags, "_get_config_var", lambda *args, **kwargs: None)
+        monkeypatch.setattr(sys, "version_info", ("L", "M", "N"))
+        assert tags.interpreter_version() == "LM"
+
+
 class TestMacOSPlatforms:
     @pytest.mark.parametrize(
         "arch, is_32bit, expected",
@@ -585,18 +624,6 @@ def test_skip_redundant_abis(self, abis):
 
 
 class TestGenericTags:
-    def test_generic_interpreter(self, monkeypatch):
-        monkeypatch.setattr(sysconfig, "get_config_var", lambda key: "42")
-        monkeypatch.setattr(tags, "interpreter_name", lambda: "sillywalk")
-        assert tags._generic_interpreter() == "sillywalk42"
-
-    def test_generic_interpreter_no_config_var(self, monkeypatch):
-        monkeypatch.setattr(sysconfig, "get_config_var", lambda _: None)
-        monkeypatch.setattr(tags, "interpreter_name", lambda: "sillywalk")
-        assert tags._generic_interpreter() == "sillywalk{}{}".format(
-            *sys.version_info[:2]
-        )
-
     @pytest.mark.skipif(
         not sysconfig.get_config_var("SOABI"), reason="SOABI not defined"
     )
@@ -642,9 +669,10 @@ def test_abi_unspecified(self, abi):
         ]
 
     def test_interpreter_default(self, monkeypatch):
-        monkeypatch.setattr(tags, "_generic_interpreter", lambda warn: "sillywalk")
+        monkeypatch.setattr(tags, "interpreter_name", lambda: "sillywalk")
+        monkeypatch.setattr(tags, "interpreter_version", lambda warn: "NN")
         result = list(tags.generic_tags(abis=["none"], platforms=["any"]))
-        assert result == [tags.Tag("sillywalk", "none", "any")]
+        assert result == [tags.Tag("sillywalkNN", "none", "any")]
 
     def test_abis_default(self, monkeypatch):
         monkeypatch.setattr(tags, "_generic_abi", lambda: iter(["abi"]))