gh-91248: Add PyFrame_GetVar() function (#95712)

Add PyFrame_GetVar() and PyFrame_GetVarString() functions to get a
frame variable by its name.

Move PyFrameObject C API tests from test_capi to test_frame.

2 files changed, 35 insertions, 21 deletions

diff --git a/Lib/test/test_capi.py b/Lib/test/test_capi.py
index 213b6d4..ea4c9de 100644
--- a/Lib/test/test_capi.py
+++ b/Lib/test/test_capi.py
@@ -1677,27 +1677,6 @@ class Test_ModuleStateAccess(unittest.TestCase):
         self.assertIs(Subclass().get_defining_module(), self.module)
 
 
-class Test_FrameAPI(unittest.TestCase):
-
-    def getframe(self):
-        return sys._getframe()
-
-    def getgenframe(self):
-        yield sys._getframe()
-
-    def test_frame_getters(self):
-        frame = self.getframe()
-        self.assertEqual(frame.f_locals, _testcapi.frame_getlocals(frame))
-        self.assertIs(frame.f_globals, _testcapi.frame_getglobals(frame))
-        self.assertIs(frame.f_builtins, _testcapi.frame_getbuiltins(frame))
-        self.assertEqual(frame.f_lasti, _testcapi.frame_getlasti(frame))
-
-    def test_frame_get_generator(self):
-        gen = self.getgenframe()
-        frame = next(gen)
-        self.assertIs(gen, _testcapi.frame_getgenerator(frame))
-
-
 SUFFICIENT_TO_DEOPT_AND_SPECIALIZE = 100
 
 class Test_Pep523API(unittest.TestCase):
diff --git a/Lib/test/test_frame.py b/Lib/test/test_frame.py
index 4b5bb7f..ada9666 100644
--- a/Lib/test/test_frame.py
+++ b/Lib/test/test_frame.py
@@ -5,6 +5,10 @@ import textwrap
 import types
 import unittest
 import weakref
+try:
+    import _testcapi
+except ImportError:
+    _testcapi = None
 
 from test import support
 from test.support.script_helper import assert_python_ok
@@ -326,5 +330,36 @@ class TestIncompleteFrameAreInvisible(unittest.TestCase):
                 gc.enable()
 
 
+@unittest.skipIf(_testcapi is None, 'need _testcapi')
+class TestCAPI(unittest.TestCase):
+    def getframe(self):
+        return sys._getframe()
+
+    def test_frame_getters(self):
+        frame = self.getframe()
+        self.assertEqual(frame.f_locals, _testcapi.frame_getlocals(frame))
+        self.assertIs(frame.f_globals, _testcapi.frame_getglobals(frame))
+        self.assertIs(frame.f_builtins, _testcapi.frame_getbuiltins(frame))
+        self.assertEqual(frame.f_lasti, _testcapi.frame_getlasti(frame))
+
+    def test_getvar(self):
+        current_frame = sys._getframe()
+        x = 1
+        self.assertEqual(_testcapi.frame_getvar(current_frame, "x"), 1)
+        self.assertEqual(_testcapi.frame_getvarstring(current_frame, b"x"), 1)
+        with self.assertRaises(NameError):
+            _testcapi.frame_getvar(current_frame, "y")
+        with self.assertRaises(NameError):
+            _testcapi.frame_getvarstring(current_frame, b"y")
+
+    def getgenframe(self):
+        yield sys._getframe()
+
+    def test_frame_get_generator(self):
+        gen = self.getgenframe()
+        frame = next(gen)
+        self.assertIs(gen, _testcapi.frame_getgenerator(frame))
+
+
 if __name__ == "__main__":
     unittest.main()