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

Author: vstinner

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 @@ def thread_deleted(_, idt=idt):
             # 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 @@ async def sock_sendfile(self, sock, file, offset=0, count=None,
         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 @@ async def sendfile(self, transport, file, offset=0, count=None,
             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 @@ async def sock_accept(self, sock):
     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 @@ async def _sock_sendfile_native(self, sock, file, offset, count):
                 "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 @@ def put(self, obj, block=True, timeout=None, *,
         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 @@ def get(self, block=True, timeout=None, *,
         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 @@ def get_nowait(self):
         """
         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 @@ def print_instruction_line(self, instr, mark_as_current):
         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.