Fix pyflakes warnings: variable is assigned to but never used (#142294)

Example of fixed warning:

    Lib/netrc.py:98:13: local variable 'toplevel'
    is assigned to but never used

Lib/_py_warnings.py

@@ -563,7 +563,6 @@ def warn_explicit(message, category, filename, lineno,
     else:
         text = message
         message = category(message)
-    modules = None
     key = (text, category, lineno)
     with _wm._lock:
         if registry is None:

Lib/_threading_local.py

@@ -57,7 +57,7 @@ class _localimpl:
             # as soon as the OS-level thread ends instead.
             local = wrlocal()
             if local is not None:
-                dct = local.dicts.pop(idt)
+                local.dicts.pop(idt)
         wrlocal = ref(self, local_deleted)
         wrthread = ref(thread, thread_deleted)
         thread.__dict__[key] = wrlocal

Lib/asyncio/base_events.py

@@ -949,7 +949,7 @@ class BaseEventLoop(events.AbstractEventLoop):
         try:
             return await self._sock_sendfile_native(sock, file,
                                                     offset, count)
-        except exceptions.SendfileNotAvailableError as exc:
+        except exceptions.SendfileNotAvailableError:
             if not fallback:
                 raise
         return await self._sock_sendfile_fallback(sock, file,
@@ -1270,7 +1270,7 @@ class BaseEventLoop(events.AbstractEventLoop):
             try:
                 return await self._sendfile_native(transport, file,
                                                    offset, count)
-            except exceptions.SendfileNotAvailableError as exc:
+            except exceptions.SendfileNotAvailableError:
                 if not fallback:
                     raise
 

Lib/asyncio/proactor_events.py

@@ -733,7 +733,7 @@ class BaseProactorEventLoop(base_events.BaseEventLoop):
     async def _sock_sendfile_native(self, sock, file, offset, count):
         try:
             fileno = file.fileno()
-        except (AttributeError, io.UnsupportedOperation) as err:
+        except (AttributeError, io.UnsupportedOperation):
             raise exceptions.SendfileNotAvailableError("not a regular file")
         try:
             fsize = os.fstat(fileno).st_size

Lib/asyncio/tools.py

@@ -244,7 +244,7 @@ def _get_awaited_by_tasks(pid: int) -> list:
             e = e.__context__
         print(f"Error retrieving tasks: {e}")
         sys.exit(1)
-    except PermissionError as e:
+    except PermissionError:
         exit_with_permission_help_text()
 
 

Lib/asyncio/unix_events.py

@@ -359,7 +359,7 @@ class _UnixSelectorEventLoop(selector_events.BaseSelectorEventLoop):
                 "os.sendfile() is not available")
         try:
             fileno = file.fileno()
-        except (AttributeError, io.UnsupportedOperation) as err:
+        except (AttributeError, io.UnsupportedOperation):
             raise exceptions.SendfileNotAvailableError("not a regular file")
         try:
             fsize = os.fstat(fileno).st_size

Lib/codeop.py

@@ -66,9 +66,9 @@ def _maybe_compile(compiler, source, filename, symbol, flags):
             try:
                 compiler(source + "\n", filename, symbol, flags=flags)
                 return None
-            except _IncompleteInputError as e:
+            except _IncompleteInputError:
                 return None
-            except SyntaxError as e:
+            except SyntaxError:
                 pass
                 # fallthrough
 

Lib/compileall.py

@@ -223,7 +223,7 @@ def compile_file(fullname, ddir=None, force=False, rx=None, quiet=0,
                     cfile = importlib.util.cache_from_source(fullname)
                     opt_cfiles[opt_level] = cfile
 
-        head, tail = name[:-3], name[-3:]
+        tail = name[-3:]
         if tail == '.py':
             if not force:
                 try:

Lib/concurrent/interpreters/_queues.py

@@ -223,7 +223,7 @@ class Queue:
         while True:
             try:
                 _queues.put(self._id, obj, unboundop)
-            except QueueFull as exc:
+            except QueueFull:
                 if timeout is not None and time.time() >= end:
                     raise  # re-raise
                 time.sleep(_delay)
@@ -258,7 +258,7 @@ class Queue:
         while True:
             try:
                 obj, unboundop = _queues.get(self._id)
-            except QueueEmpty as exc:
+            except QueueEmpty:
                 if timeout is not None and time.time() >= end:
                     raise  # re-raise
                 time.sleep(_delay)
@@ -277,7 +277,7 @@ class Queue:
         """
         try:
             obj, unboundop = _queues.get(self._id)
-        except QueueEmpty as exc:
+        except QueueEmpty:
             raise  # re-raise
         if unboundop is not None:
             assert obj is None, repr(obj)

Lib/dis.py

@@ -530,7 +530,6 @@ class Formatter:
         fields.append(instr.opname.ljust(_OPNAME_WIDTH))
         # Column: Opcode argument
         if instr.arg is not None:
-            arg = repr(instr.arg)
             # If opname is longer than _OPNAME_WIDTH, we allow it to overflow into
             # the space reserved for oparg. This results in fewer misaligned opargs
             # in the disassembly output.

Lib/encodings/uu_codec.py

@@ -56,7 +56,7 @@ def uu_decode(input, errors='strict'):
             break
         try:
             data = binascii.a2b_uu(s)
-        except binascii.Error as v:
+        except binascii.Error:
             # Workaround for broken uuencoders by /Fredrik Lundh
             nbytes = (((s[0]-32) & 63) * 4 + 5) // 3
             data = binascii.a2b_uu(s[:nbytes])

Lib/ftplib.py

@@ -314,9 +314,9 @@ class FTP:
         port = sock.getsockname()[1] # Get proper port
         host = self.sock.getsockname()[0] # Get proper host
         if self.af == socket.AF_INET:
-            resp = self.sendport(host, port)
+            self.sendport(host, port)
         else:
-            resp = self.sendeprt(host, port)
+            self.sendeprt(host, port)
         if self.timeout is not _GLOBAL_DEFAULT_TIMEOUT:
             sock.settimeout(self.timeout)
         return sock
@@ -455,7 +455,7 @@ class FTP:
         """
         if callback is None:
             callback = print_line
-        resp = self.sendcmd('TYPE A')
+        self.sendcmd('TYPE A')
         with self.transfercmd(cmd) as conn, \
                  conn.makefile('r', encoding=self.encoding) as fp:
             while 1:
@@ -951,7 +951,7 @@ def test():
         elif file[:2] == '-d':
             cmd = 'CWD'
             if file[2:]: cmd = cmd + ' ' + file[2:]
-            resp = ftp.sendcmd(cmd)
+            ftp.sendcmd(cmd)
         elif file == '-p':
             ftp.set_pasv(not ftp.passiveserver)
         else:

Lib/functools.py

@@ -687,7 +687,7 @@ def _lru_cache_wrapper(user_function, maxsize, typed, _CacheInfo):
                     # still adjusting the links.
                     root = oldroot[NEXT]
                     oldkey = root[KEY]
-                    oldresult = root[RESULT]
+                    oldresult = root[RESULT]  # noqa: F841
                     root[KEY] = root[RESULT] = None
 
                     # Now update the cache dictionary.

Lib/idlelib/pyshell.py

@@ -498,7 +498,6 @@ class ModifiedInterpreter(InteractiveInterpreter):
         self.rpcclt.close()
         self.terminate_subprocess()
         console = self.tkconsole
-        was_executing = console.executing
         console.executing = False
         self.spawn_subprocess()
         try:

Lib/idlelib/textview.py

@@ -129,8 +129,8 @@ class ViewWindow(Toplevel):
         self.title(title)
         self.viewframe = ViewFrame(self, contents, wrap=wrap)
         self.protocol("WM_DELETE_WINDOW", self.ok)
-        self.button_ok = button_ok = Button(self, text='Close',
-                                            command=self.ok, takefocus=False)
+        self.button_ok = Button(self, text='Close',
+                                command=self.ok, takefocus=False)
         self.viewframe.pack(side='top', expand=True, fill='both')
 
         self.is_modal = modal

Lib/imaplib.py

@@ -808,7 +808,7 @@ class IMAP4:
         """
 
         name = 'PROXYAUTH'
-        return self._simple_command('PROXYAUTH', user)
+        return self._simple_command(name, user)
 
 
     def rename(self, oldmailbox, newmailbox):
@@ -1310,7 +1310,7 @@ class IMAP4:
 
             try:
                 self._get_response()
-            except self.abort as val:
+            except self.abort:
                 if __debug__:
                     if self.debug >= 1:
                         self.print_log()
@@ -1867,7 +1867,7 @@ if __name__ == '__main__':
 
     try:
         optlist, args = getopt.getopt(sys.argv[1:], 'd:s:')
-    except getopt.error as val:
+    except getopt.error:
         optlist, args = (), ()
 
     stream_command = None

Lib/inspect.py

@@ -2140,7 +2140,6 @@ def _signature_strip_non_python_syntax(signature):
 
     current_parameter = 0
     OP = token.OP
-    ERRORTOKEN = token.ERRORTOKEN
 
     # token stream always starts with ENCODING token, skip it
     t = next(token_stream)

Lib/modulefinder.py

@@ -400,7 +400,6 @@ class ModuleFinder:
                 yield "relative_import", (level, fromlist, name)
 
     def scan_code(self, co, m):
-        code = co.co_code
         scanner = self.scan_opcodes
         for what, args in scanner(co):
             if what == "store":

Lib/multiprocessing/connection.py

@@ -709,8 +709,7 @@ if sys.platform == 'win32':
                 # written data and then disconnected -- see Issue 14725.
             else:
                 try:
-                    res = _winapi.WaitForMultipleObjects(
-                        [ov.event], False, INFINITE)
+                    _winapi.WaitForMultipleObjects([ov.event], False, INFINITE)
                 except:
                     ov.cancel()
                     _winapi.CloseHandle(handle)

Lib/netrc.py

@@ -95,7 +95,7 @@ class netrc:
         while 1:
             # Look for a machine, default, or macdef top-level keyword
             saved_lineno = lexer.lineno
-            toplevel = tt = lexer.get_token()
+            tt = lexer.get_token()
             if not tt:
                 break
             elif tt[0] == '#':

Lib/ntpath.py

@@ -726,7 +726,7 @@ else:
             try:
                 if _getfinalpathname(spath) == path:
                     path = spath
-            except ValueError as ex:
+            except ValueError:
                 # Unexpected, as an invalid path should not have gained a prefix
                 # at any point, but we ignore this error just in case.
                 pass

Lib/optparse.py

@@ -1372,7 +1372,7 @@ class OptionParser (OptionContainer):
         self.values = values
 
         try:
-            stop = self._process_args(largs, rargs, values)
+            self._process_args(largs, rargs, values)
         except (BadOptionError, OptionValueError) as err:
             self.error(str(err))
 

Lib/pickle.py

@@ -1169,7 +1169,6 @@ class _Pickler:
 
     def save_global(self, obj, name=None):
         write = self.write
-        memo = self.memo
 
         if name is None:
             name = getattr(obj, '__qualname__', None)
@@ -1756,7 +1755,7 @@ class _Unpickler:
         i = self.read(1)[0]
         try:
             self.append(self.memo[i])
-        except KeyError as exc:
+        except KeyError:
             msg = f'Memo value not found at index {i}'
             raise UnpicklingError(msg) from None
     dispatch[BINGET[0]] = load_binget
@@ -1765,7 +1764,7 @@ class _Unpickler:
         i, = unpack('<I', self.read(4))
         try:
             self.append(self.memo[i])
-        except KeyError as exc:
+        except KeyError:
             msg = f'Memo value not found at index {i}'
             raise UnpicklingError(msg) from None
     dispatch[LONG_BINGET[0]] = load_long_binget

Lib/platform.py

@@ -305,8 +305,7 @@ def _syscmd_ver(system='', release='', version='',
                                            text=True,
                                            encoding="locale",
                                            shell=True)
-        except (OSError, subprocess.CalledProcessError) as why:
-            #print('Command %s failed: %s' % (cmd, why))
+        except (OSError, subprocess.CalledProcessError):
             continue
         else:
             break

Lib/pyclbr.py

@@ -158,7 +158,6 @@ def _readmodule(module, path, inpackage=None):
         return _readmodule(submodule, parent['__path__'], package)
 
     # Search the path for the module.
-    f = None
     if inpackage is not None:
         search_path = path
     else:

Lib/re/_parser.py

@@ -455,7 +455,6 @@ def _parse_sub(source, state, verbose, nested):
     items = []
     itemsappend = items.append
     sourcematch = source.match
-    start = source.tell()
     while True:
         itemsappend(_parse(source, state, verbose, nested + 1,
                            not nested and not items))

Lib/subprocess.py

@@ -1235,7 +1235,7 @@ class Popen:
             finally:
                 self._communication_started = True
             try:
-                sts = self.wait(timeout=self._remaining_time(endtime))
+                self.wait(timeout=self._remaining_time(endtime))
             except TimeoutExpired as exc:
                 exc.timeout = timeout
                 raise

Lib/tempfile.py

@@ -691,7 +691,7 @@ else:
             fd, name = _mkstemp_inner(dir, prefix, suffix, flags, output_type)
             try:
                 _os.unlink(name)
-            except BaseException as e:
+            except BaseException:
                 _os.close(fd)
                 raise
             return fd

Lib/tokenize.py

@@ -403,7 +403,7 @@ def detect_encoding(readline):
             return None
         encoding = _get_normal_name(match.group(1).decode())
         try:
-            codec = lookup(encoding)
+            lookup(encoding)
         except LookupError:
             # This behaviour mimics the Python interpreter
             if filename is None:

Lib/turtle.py

@@ -565,7 +565,7 @@ class TurtleScreenBase(object):
         """Check if the string color is a legal Tkinter color string.
         """
         try:
-            rgb = self.cv.winfo_rgb(color)
+            self.cv.winfo_rgb(color)
             ok = True
         except TK.TclError:
             ok = False
@@ -3747,7 +3747,7 @@ class RawTurtle(TPen, TNavigator):
         if action == "rot":
             angle, degPAU = data
             self._rotate(-angle*degPAU/self._degreesPerAU)
-            dummy = self.undobuffer.pop()
+            self.undobuffer.pop()
         elif action == "stamp":
             stitem = data[0]
             self.clearstamp(stitem)

Lib/urllib/parse.py

@@ -1062,7 +1062,7 @@ def urlencode(query, doseq=False, safe='', encoding=None, errors=None,
             else:
                 try:
                     # Is this a sufficient test for sequence-ness?
-                    x = len(v)
+                    len(v)
                 except TypeError:
                     # not a sequence
                     v = quote_via(str(v), safe, encoding, errors)

Lib/venv/__init__.py

@@ -306,7 +306,6 @@ class EnvBuilder:
             binpath = context.bin_path
             path = context.env_exe
             copier = self.symlink_or_copy
-            dirname = context.python_dir
             copier(context.executable, path)
             if not os.path.islink(path):
                 os.chmod(path, 0o755)