gh-124022: Fix bug where class docstring is removed in interactive mode

Lib/test/test_compile.py

@@ -902,6 +902,22 @@ def with_const_expression():
                 self.assertIsNone(ns['with_fstring'].__doc__)
                 self.assertIsNone(ns['with_const_expression'].__doc__)
 
+    @support.cpython_only
+    def test_docstring_interactive_mode(self):
+        src = textwrap.dedent("""
+            def with_docstring():
+                "docstring"
+        """)
+        for opt in [0, 1, 2]:
+            with self.subTest(opt=opt):
+                code = compile(src, "<test>", "single", optimize=opt)
+                ns = {}
+                exec(code, ns)
+                if opt < 2:
+                    self.assertEqual(ns['with_docstring'].__doc__, "docstring")
+                else:
+                    self.assertIsNone(ns['with_docstring'].__doc__)
+
     @support.cpython_only
     def test_docstring_omitted(self):
         # See gh-115347
@@ -919,12 +935,13 @@ class C:
                 return h
         """)
         for opt in [-1, 0, 1, 2]:
-            with self.subTest(opt=opt):
-                code = compile(src, "<test>", "exec", optimize=opt)
-                output = io.StringIO()
-                with contextlib.redirect_stdout(output):
-                    dis.dis(code)
-                self.assertNotIn('NOP' , output.getvalue())
+            for mode in ["exec",  "single"]:
+                with self.subTest(opt=opt, mode=mode):
+                    code = compile(src, "<test>", mode, optimize=opt)
+                    output = io.StringIO()
+                    with contextlib.redirect_stdout(output):
+                        dis.dis(code)
+                    self.assertNotIn('NOP' , output.getvalue())
 
     def test_dont_merge_constants(self):
         # Issue #25843: compile() must not merge constants which are equal

Misc/NEWS.d/next/Core_and_Builtins/2024-09-12-21-53-26.gh-issue-124022.fQzUiW.rst

@@ -0,0 +1 @@
+Fix bug where docstring it removed from classes in interactive mode.

Python/codegen.c

@@ -758,23 +758,21 @@ _PyCodegen_Body(compiler *c, location loc, asdl_stmt_seq *stmts)
         return SUCCESS;
     }
     Py_ssize_t first_instr = 0;
-    if (!IS_INTERACTIVE(c)) {
-        PyObject *docstring = _PyAST_GetDocString(stmts);
-        if (docstring) {
-            first_instr = 1;
-            /* set docstring */
-            assert(OPTIMIZATION_LEVEL(c) < 2);
-            PyObject *cleandoc = _PyCompile_CleanDoc(docstring);
-            if (cleandoc == NULL) {
-                return ERROR;
-            }
-            stmt_ty st = (stmt_ty)asdl_seq_GET(stmts, 0);
-            assert(st->kind == Expr_kind);
-            location loc = LOC(st->v.Expr.value);
-            ADDOP_LOAD_CONST(c, loc, cleandoc);
-            Py_DECREF(cleandoc);
-            RETURN_IF_ERROR(codegen_nameop(c, NO_LOCATION, &_Py_ID(__doc__), Store));
+    PyObject *docstring = _PyAST_GetDocString(stmts);
+    if (docstring) {
+        first_instr = 1;
+        /* set docstring */
+        assert(OPTIMIZATION_LEVEL(c) < 2);
+        PyObject *cleandoc = _PyCompile_CleanDoc(docstring);
+        if (cleandoc == NULL) {
+            return ERROR;
         }
+        stmt_ty st = (stmt_ty)asdl_seq_GET(stmts, 0);
+        assert(st->kind == Expr_kind);
+        location loc = LOC(st->v.Expr.value);
+        ADDOP_LOAD_CONST(c, loc, cleandoc);
+        Py_DECREF(cleandoc);
+        RETURN_IF_ERROR(codegen_nameop(c, NO_LOCATION, &_Py_ID(__doc__), Store));
     }
     for (Py_ssize_t i = first_instr; i < asdl_seq_LEN(stmts); i++) {
         VISIT(c, stmt, (stmt_ty)asdl_seq_GET(stmts, i));