fix types

IPython/utils/_process_common.py

@@ -14,18 +14,19 of subprocess utilities, and it contains tools that are common to all of them.
 #-----------------------------------------------------------------------------
 # Imports
 #-----------------------------------------------------------------------------
-import subprocess
+import os
 import shlex
+import subprocess
 import sys
-import os
-from typing import Callable, Optional, Union, List
+from typing import IO, Any, Callable, List, Union
+
 from IPython.utils import py3compat
 
 #-----------------------------------------------------------------------------
 # Function definitions
 #-----------------------------------------------------------------------------
 
-def read_no_interrupt(p: subprocess.Popen) -> str:
+def read_no_interrupt(stream: IO[Any]) -> bytes:
     """Read from a pipe ignoring EINTR errors.
 
     This is necessary because when reading from pipes with GUI event loops
@@ -34,7 +35,7 def read_no_interrupt(p: subprocess.Popen) -> str:
     import errno
 
     try:
-        return p.read()
+        return stream.read()
     except IOError as err:
         if err.errno != errno.EINTR:
             raise

IPython/utils/_process_win32.py

@@ -15,23 +15,23 This file is only meant to be imported by process.py, not by end-users.
 #-----------------------------------------------------------------------------
 
 # stdlib
+import ctypes
 import os
+import subprocess
 import sys
-import ctypes
 import time
-
-from ctypes import c_int, POINTER
-from ctypes.wintypes import LPCWSTR, HLOCAL
-from subprocess import STDOUT, TimeoutExpired
+from ctypes import POINTER, c_int
+from ctypes.wintypes import HLOCAL, LPCWSTR
+from subprocess import STDOUT
 from threading import Thread
-import subprocess
+from types import TracebackType
+from typing import IO, Any, List, Optional
 
-from typing import Optional, List
-import traceback
+from . import py3compat
+from ._process_common import arg_split as py_arg_split
 
 # our own imports
-from ._process_common import read_no_interrupt, process_handler, arg_split as py_arg_split
-from . import py3compat
+from ._process_common import process_handler, read_no_interrupt
 from .encoding import DEFAULT_ENCODING
 
 #-----------------------------------------------------------------------------
@@ -72,7 +72,7 class AvoidUNCPath:
             return None
 
     def __exit__(
-        self, exc_type: Optional[type], exc_value: Optional[BaseException], traceback
+        self, exc_type: Optional[type[BaseException]], exc_value: Optional[BaseException], traceback:TracebackType
     ) -> None:
         if self.is_unc_path:
             os.chdir(self.path)
@@ -82,18 +82,23 def _system_body(p: subprocess.Popen) -> int:
     """Callback for _system."""
     enc = DEFAULT_ENCODING
 
+    # Dec 2024: in both of these functions, I'm not sure why we .splitlines()
+    # the bytes and then decode each line individually instead of just decoding
+    # the whole thing at once.
     def stdout_read() -> None:
         try:
-            for line in read_no_interrupt(p.stdout).splitlines():
-                line = line.decode(enc, "replace")
+            assert p.stdout is not None
+            for byte_line in read_no_interrupt(p.stdout).splitlines():
+                line = byte_line.decode(enc, "replace")
                 print(line, file=sys.stdout)
         except Exception as e:
             print(f"Error reading stdout: {e}", file=sys.stderr)
 
     def stderr_read() -> None:
         try:
-            for line in read_no_interrupt(p.stderr).splitlines():
-                line = line.decode(enc, "replace")
+            assert p.stderr is not None
+            for byte_line in read_no_interrupt(p.stderr).splitlines():
+                line = byte_line.decode(enc, "replace")
                 print(line, file=sys.stderr)
         except Exception as e:
             print(f"Error reading stderr: {e}", file=sys.stderr)
@@ -204,7 +209,7 try:
             )
             if arg is not None
         ]
-        retval = LocalFree(result_pointer)
+        LocalFree(result_pointer)
         return result
 except AttributeError:
     arg_split = py_arg_split