gh-137671 suggest name for "ModuleNotFoundError"

Lib/idlelib/idle_test/test_run.py

@@ -45,14 +45,18 @@ def __eq__(self, other):
             ('int.reel', AttributeError,
                  "type object 'int' has no attribute 'reel'. "
                  "Did you mean: 'real'?\n"),
+            (r'raise NameError("123\n456")', NameError, "123\n456\n"),
             )
 
     @force_not_colorized
     def test_get_message(self):
         for code, exc, msg in self.data:
             with self.subTest(code=code):
                 try:
-                    eval(compile(code, '', 'eval'))
+                    if "raise" not in code:
+                        eval(compile(code, '', 'eval'))
+                    else:
+                        exec(compile(code, '', 'exec')) # code r"raise NameError("123\n456")" cannot run in "eval" mode: SyntaxError
                 except exc:
                     typ, val, tb = sys.exc_info()
                     actual = run.get_message_lines(typ, val, tb)[0]
@@ -64,15 +68,26 @@ def test_get_message(self):
                        new_callable=lambda: (lambda t, e: None))
     def test_get_multiple_message(self, mock):
         d = self.data
-        data2 = ((d[0], d[1]), (d[1], d[2]), (d[2], d[0]))
+        data2 = ((d[0], d[1]),
+                 (d[1], d[2]),
+                 (d[2], d[3]),
+                 (d[3], d[0]),
+                 (d[1], d[3]),
+                 (d[0], d[2]))
         subtests = 0
         for (code1, exc1, msg1), (code2, exc2, msg2) in data2:
             with self.subTest(codes=(code1,code2)):
                 try:
-                    eval(compile(code1, '', 'eval'))
+                    if "raise" not in code1:
+                        eval(compile(code1, '', 'eval'))
+                    else:
+                        exec(compile(code1, '', 'exec'))
                 except exc1:
                     try:
-                        eval(compile(code2, '', 'eval'))
+                        if "raise" not in code2:
+                            eval(compile(code2, '', 'eval'))
+                        else:
+                            exec(compile(code2, '', 'exec'))
                     except exc2:
                         with captured_stderr() as output:
                             run.print_exception()

Lib/idlelib/run.py

@@ -230,12 +230,20 @@ def show_socket_error(err, address):
 
 def get_message_lines(typ, exc, tb):
     "Return line composing the exception message."
-    if typ in (AttributeError, NameError):
+    if typ in (AttributeError, NameError, ImportError):
         # 3.10+ hints are not directly accessible from python (#44026).
         err = io.StringIO()
         with contextlib.redirect_stderr(err):
             sys.__excepthook__(typ, exc, tb)
-        return [err.getvalue().split("\n")[-2] + "\n"]
+        err_list = err.getvalue().split("\n")[1:]
+
+        for i in range(len(err_list)):
+            if err_list[i].startswith(" "):
+                continue
+            else:
+                err_list = err_list[i:-1]
+                break
+        return ["\n".join(err_list) + "\n"] # The unmerged gh-135511
     else:
         return traceback.format_exception_only(typ, exc)
 

Lib/test/test_unittest/test_loader.py

@@ -335,7 +335,7 @@ def test_loadTestsFromName__unknown_attr_name_on_package(self):
         loader = unittest.TestLoader()
 
         suite = loader.loadTestsFromName('unittest.sdasfasfasdf')
-        expected = "No module named 'unittest.sdasfasfasdf'"
+        expected = "module 'unittest' has no child module 'sdasfasfasdf'"
         error, test = self.check_deferred_error(loader, suite)
         self.assertIn(
             expected, error,

Lib/traceback.py

@@ -1107,11 +1107,19 @@ def __init__(self, exc_type, exc_value, exc_traceback, *, limit=None,
             suggestion = _compute_suggestion_error(exc_value, exc_traceback, wrong_name)
             if suggestion:
                 self._str += f". Did you mean: '{suggestion}'?"
-        elif exc_type and issubclass(exc_type, ModuleNotFoundError) and \
-                sys.flags.no_site and \
-                getattr(exc_value, "name", None) not in sys.stdlib_module_names:
-            self._str += (". Site initialization is disabled, did you forget to "
-                + "add the site-packages directory to sys.path?")
+        elif exc_type and issubclass(exc_type, ModuleNotFoundError) and getattr(exc_value, "name", None):
+            wrong_name = getattr(exc_value, "name", None)
+            suggestion = _compute_suggestion_error(exc_value, exc_traceback, wrong_name)
+            self._str = exc_value.msg
+            if suggestion:                
+                self._str += f". Did you mean: '{suggestion}'?"
+            if sys.flags.no_site and getattr(exc_value, "name", None) not in sys.stdlib_module_names:
+                if not suggestion:
+                    self._str += (". Site initialization is disabled, did you forget to "
+                    + "add the site-packages directory to sys.path?")
+                else:
+                    self._str += ("Or did you forget to add the site-packages directory to sys.path? The "
+                                 + "site initialization is disabled")
         elif exc_type and issubclass(exc_type, (NameError, AttributeError)) and \
                 getattr(exc_value, "name", None) is not None:
             wrong_name = getattr(exc_value, "name", None)
@@ -1634,7 +1642,111 @@ def _compute_suggestion_error(exc_value, tb, wrong_name):
             if wrong_name[:1] != '_':
                 d = [x for x in d if x[:1] != '_']
         except Exception:
-            return None
+            if not isinstance(exc_value, ModuleNotFoundError):
+                return None
+            scan_dir, find_all_packages = _find_all_packages()
+            import os
+            list_d = find_all_packages()            
+            _module_name = exc_value.name
+            wrong_name_list = _module_name.split(".")
+            module_name = wrong_name_list[0]
+            if module_name not in sys.modules:                
+                wrong_name = module_name
+                exc_value.msg = f"No module named '{module_name}'"
+                if len(wrong_name_list) == 1:                    
+                    if (_closed_name := _calculate_closed_name(module_name, sorted(sys.stdlib_module_names))):
+                        return _closed_name # stdlib first
+                    _close_name_list = []
+                    for i in list_d:
+                        module_result = _calculate_closed_name(wrong_name, i)
+                        if module_result:
+                            _close_name_list.append(module_result)
+                    _close_name_list.sort()
+                    if _close_name_list:
+                        return _close_name_list[0]    
+                    else:
+                        return None
+                else:                   
+                    if wrong_name in sum(list_d, []):
+                        path = ""
+                        for i in sys.path:
+                            if i and isinstance(i, str) and not i.endswith("idlelib"):
+                                if wrong_name in scan_dir(i):
+                                    path = f"{i}/{wrong_name}"
+                                    break
+                        else:
+                            if (_closed_name := _calculate_closed_name(module_name, sorted(sys.stdlib_module_names))):
+                                return _closed_name
+                            _close_name_list = []
+                            for i in list_d:
+                                module_result = _calculate_closed_name(wrong_name, i)
+                                if module_result:
+                                    _close_name_list.append(module_result)
+                            _close_name_list.sort()
+                            if _close_name_list:
+                                return _close_name_list[0]    
+                            else:
+                                return None
+                    else:
+                        if (_closed_name := _calculate_closed_name(module_name, sorted(sys.stdlib_module_names))):
+                            return _closed_name
+                        _close_name_list = []
+                        for i in list_d:
+                            module_result = _calculate_closed_name(wrong_name, i)
+                            if module_result:
+                                _close_name_list.append(module_result)
+                        _close_name_list.sort()
+                        if _close_name_list:
+                            return _close_name_list[0]    
+                        else:
+                            return None
+
+                    if not os.path.exists(path) or not os.path.isdir(path):
+                        exc_value.msg = f"module '{module_name}' has no child module '{wrong_name_list[1]}'; '{module_name}' is not a package"
+                        return None
+                    index = 0
+                    for i in wrong_name_list[1:]:
+                        index += 1
+                        _child_modules_d = scan_dir(path)
+                        original_module_name = module_name
+                        if wrong_name_list[index] not in _child_modules_d:
+                            exc_value.msg = f"module '{module_name}' has no child module '{i}'"
+                            wrong_name = i
+                            d = _child_modules_d
+                            break
+                        path += f"/{i}"
+                        if not os.path.exists(path) or not os.path.isdir(path) and len(wrong_name_list) > index + 1:
+                            module_name += "." + i
+                            exc_value.msg = f"module '{module_name}' has no child module '{wrong_name_list[index + 1]}'; '{module_name}' is not a package"
+                            return None
+                        module_name += "." + i
+                exc_value.args = (exc_value.msg,)
+            else:
+                if hasattr(sys.modules[module_name], '__path__') and len(wrong_name_list)>1:
+                    index = 0
+                    for i in wrong_name_list[1:]:
+                        index += 1
+                        original_module_name = module_name
+                        exc_value.msg = f"module '{module_name}' has no child module '{i}'"
+                        exc_value.args = (exc_value.msg,)
+                        module_name += "." + i
+                        if module_name not in sys.modules:
+                            wrong_name = i
+                            d = scan_dir(sys.modules[original_module_name].__path__[0])
+                            break
+                        else:
+                            if hasattr(sys.modules[module_name], '__path__'):
+                                continue
+                            else:
+                                if len(wrong_name_list) > index + 1:                                    
+                                    exc_value.msg = f"module '{module_name}' has no child module '{wrong_name_list[index+1]}'; '{module_name}' is not a package"
+                                exc_value.args = (exc_value.msg,)
+                                return None
+                else:
+                    if len(wrong_name_list) > 1:
+                        exc_value.msg = f"module '{module_name}' has no child module '{wrong_name_list[1]}'; '{module_name}' is not a package"
+                    exc_value.args = (exc_value.msg,)
+                    return None
     else:
         assert isinstance(exc_value, NameError)
         # find most recent frame
@@ -1661,13 +1773,14 @@ def _compute_suggestion_error(exc_value, tb, wrong_name):
             if has_wrong_name:
                 return f"self.{wrong_name}"
 
+    return _calculate_closed_name(wrong_name, d)
+
+def _calculate_closed_name(wrong_name, d):
     try:
         import _suggestions
+        return _suggestions._generate_suggestions(d, wrong_name)
     except ImportError:
         pass
-    else:
-        return _suggestions._generate_suggestions(d, wrong_name)
-
     # Compute closest match
 
     if len(d) > _MAX_CANDIDATE_ITEMS:
@@ -1693,6 +1806,54 @@ def _compute_suggestion_error(exc_value, tb, wrong_name):
             best_distance = current_distance
     return suggestion
 
+def _find_all_packages():
+    import os
+    import sys
+    from importlib import machinery
+
+    def scan_dir(path):
+        """
+        Return all of the packages in the path without import
+        contains：
+          - .py file
+          - directory with "__init__.py"
+          - the .pyd/so file that has right ABI
+        """
+        if not os.path.isdir(path):
+            return []
+
+        suffixes = machinery.EXTENSION_SUFFIXES
+        result = []
+
+        for name in os.listdir(path):
+            full_path = os.path.join(path, name)
+
+            # .py file
+            if name.endswith(".py") and os.path.isfile(full_path):
+                modname = name[:-3]
+                if modname.isidentifier():
+                    result.append(modname)
+
+            # directory with "__init__.py"
+            elif os.path.isdir(full_path):
+                init_file = os.path.join(full_path, "__init__.py")
+                if os.path.isfile(init_file) and name.isidentifier():
+                    result.append(name)
+
+            # the .pyd/so file that has right ABI
+            elif os.path.isfile(full_path):
+                for suf in suffixes:
+                    if name.endswith(suf):
+                        modname = name[:-len(suf)]
+                        if modname.isidentifier():
+                            result.append(modname)
+                        break
+
+        return sorted(result)
+
+    def find_all_packages():
+        return [scan_dir(i) if i and isinstance(i, str) and not i.endswith("idlelib") else [] for i in sys.path] + [sorted(sys.builtin_module_names)]
+    return scan_dir, find_all_packages
 
 def _levenshtein_distance(a, b, max_cost):
     # A Python implementation of Python/suggestions.c:levenshtein_distance.

Misc/NEWS.d/next/IDLE/2025-08-08-10-50-59.gh-issue-135511.9Rw5Zg.rst

@@ -0,0 +1,2 @@
+Fix the missing error message in "NameError" and "AttributeError" in IDLE
+when "\n" in message