Remove/improve some more casts to Any (#14828)

AlexWaygood · web-flow · commit c91849dc2d65 · 2023-03-04T10:00:10.000-08:00
diff --git a/mypy/fastparse.py b/mypy/fastparse.py
@@ -351,8 +351,7 @@ def parse_type_comment(
     else:
         extra_ignore = TYPE_IGNORE_PATTERN.match(type_comment)
         if extra_ignore:
-            # Typeshed has a non-optional return type for group!
-            tag: str | None = cast(Any, extra_ignore).group(1)
+            tag: str | None = extra_ignore.group(1)
             ignored: list[str] | None = parse_type_ignore_tag(tag)
             if ignored is None:
                 if errors is not None:
diff --git a/mypy/semanal.py b/mypy/semanal.py
@@ -5810,7 +5810,7 @@ def _get_node_for_class_scoped_import(
         # mypyc is absolutely convinced that `symbol_node` narrows to a Var in the following,
         # when it can also be a FuncBase. Once fixed, `f` in the following can be removed.
         # See also https://github.com/mypyc/mypyc/issues/892
-        f = cast(Any, lambda x: x)
+        f: Callable[[object], Any] = lambda x: x
         if isinstance(f(symbol_node), (Decorator, FuncBase, Var)):
             # For imports in class scope, we construct a new node to represent the symbol and
             # set its `info` attribute to `self.type`.
diff --git a/mypyc/codegen/literals.py b/mypyc/codegen/literals.py
@@ -1,14 +1,19 @@
 from __future__ import annotations
 
-from typing import Any, FrozenSet, List, Tuple, Union, cast
-from typing_extensions import Final
+from typing import FrozenSet, List, Tuple, Union
+from typing_extensions import Final, TypeGuard
 
 # Supported Python literal types. All tuple / frozenset items must have supported
 # literal types as well, but we can't represent the type precisely.
 LiteralValue = Union[
     str, bytes, int, bool, float, complex, Tuple[object, ...], FrozenSet[object], None
 ]
 
+
+def _is_literal_value(obj: object) -> TypeGuard[LiteralValue]:
+    return isinstance(obj, (str, bytes, int, float, complex, tuple, frozenset, type(None)))
+
+
 # Some literals are singletons and handled specially (None, False and True)
 NUM_SINGLETONS: Final = 3
 
@@ -55,13 +60,15 @@ def record_literal(self, value: LiteralValue) -> None:
             tuple_literals = self.tuple_literals
             if value not in tuple_literals:
                 for item in value:
-                    self.record_literal(cast(Any, item))
+                    assert _is_literal_value(item)
+                    self.record_literal(item)
                 tuple_literals[value] = len(tuple_literals)
         elif isinstance(value, frozenset):
             frozenset_literals = self.frozenset_literals
             if value not in frozenset_literals:
                 for item in value:
-                    self.record_literal(cast(Any, item))
+                    assert _is_literal_value(item)
+                    self.record_literal(item)
                 frozenset_literals[value] = len(frozenset_literals)
         else:
             assert False, "invalid literal: %r" % value
@@ -159,7 +166,8 @@ def _encode_collection_values(
             value = value_by_index[i]
             result.append(str(len(value)))
             for item in value:
-                index = self.literal_index(cast(Any, item))
+                assert _is_literal_value(item)
+                index = self.literal_index(item)
                 result.append(str(index))
         return result
 
