refactor: reorganize imports and improve error message handling in remote pdb tests

Signed-off-by: Frost Ming <[email protected]>

Author: frostming

Lib/test/test_remote_pdb.py

@@ -2,6 +2,7 @@
 import itertools
 import json
 import os
+import pdb
 import re
 import signal
 import socket
@@ -10,14 +11,25 @@
 import textwrap
 import unittest
 import unittest.mock
-from contextlib import closing, contextmanager, redirect_stdout, redirect_stderr, ExitStack
-from test.support import is_wasi, cpython_only, force_color, requires_subprocess, SHORT_TIMEOUT, subTests
-from test.support.os_helper import TESTFN, unlink
+from contextlib import (
+    ExitStack,
+    closing,
+    contextmanager,
+    redirect_stderr,
+    redirect_stdout,
+)
+from pdb import _PdbClient, _PdbServer
 from typing import List
 
-import pdb
-from pdb import _PdbServer, _PdbClient
-
+from test.support import (
+    SHORT_TIMEOUT,
+    cpython_only,
+    force_color,
+    is_wasi,
+    requires_subprocess,
+    subTests,
+)
+from test.support.os_helper import TESTFN, unlink
 
 if not sys.is_remote_debug_enabled():
     raise unittest.SkipTest('remote debugging is disabled')
@@ -1594,11 +1606,11 @@ def test_attach_to_non_existent_process(self):
         with force_color(False):
             result = subprocess.run([sys.executable, "-m", "pdb", "-p", "999999"], text=True, capture_output=True)
         self.assertNotEqual(result.returncode, 0)
-        error = (
-            "The specified process cannot be attached to due to insufficient permissions."
-            if sys.platform == "darwin" else
-            "Cannot attach to pid 999999, please make sure that the process exists"
-        )
+        if sys.platform == "darwin":
+            # On MacOS, attaching to a non-existent process gives PermissionError
+            error = "The specified process cannot be attached to due to insufficient permissions"
+        else:
+            error = "Cannot attach to pid 999999, please make sure that the process exists"
         self.assertIn(error, result.stdout)