mypy: run pyupgrade (#12711)

Re-attempt of #10741
Ran: `pyupgrade --py36-plus $(fd -e py) --keep-runtime-typing`
I mostly only needed to change things where NamedTuple comments got
dropped.
Notably, I omitted changes to pyinfo.py

mypy/binder.py

@@ -189,7 +189,7 @@ def update_from_options(self, frames: List[Frame]) -> bool:
 
         frames = [f for f in frames if not f.unreachable]
         changed = False
-        keys = set(key for f in frames for key in f.types)
+        keys = {key for f in frames for key in f.types}
 
         for key in keys:
             current_value = self._get(key)

mypy/checker.py

@@ -97,26 +97,23 @@
 DeferredNodeType: _TypeAlias = Union[FuncDef, LambdaExpr, OverloadedFuncDef, Decorator]
 FineGrainedDeferredNodeType: _TypeAlias = Union[FuncDef, MypyFile, OverloadedFuncDef]
 
+
 # A node which is postponed to be processed during the next pass.
 # In normal mode one can defer functions and methods (also decorated and/or overloaded)
 # and lambda expressions. Nested functions can't be deferred -- only top-level functions
 # and methods of classes not defined within a function can be deferred.
-DeferredNode = NamedTuple(
-    'DeferredNode',
-    [
-        ('node', DeferredNodeType),
-        ('active_typeinfo', Optional[TypeInfo]),  # And its TypeInfo (for semantic analysis
-                                                  # self type handling)
-    ])
+class DeferredNode(NamedTuple):
+    node: DeferredNodeType
+    # And its TypeInfo (for semantic analysis self type handling
+    active_typeinfo: Optional[TypeInfo]
+
 
 # Same as above, but for fine-grained mode targets. Only top-level functions/methods
 # and module top levels are allowed as such.
-FineGrainedDeferredNode = NamedTuple(
-    'FineGrainedDeferredNode',
-    [
-        ('node', FineGrainedDeferredNodeType),
-        ('active_typeinfo', Optional[TypeInfo]),
-    ])
+class FineGrainedDeferredNode(NamedTuple):
+    node: FineGrainedDeferredNodeType
+    active_typeinfo: Optional[TypeInfo]
+
 
 # Data structure returned by find_isinstance_check representing
 # information learned from the truth or falsehood of a condition.  The
@@ -131,25 +128,23 @@
 # (such as two references to the same variable). TODO: it would
 # probably be better to have the dict keyed by the nodes' literal_hash
 # field instead.
-
 TypeMap: _TypeAlias = Optional[Dict[Expression, Type]]
 
+
 # An object that represents either a precise type or a type with an upper bound;
 # it is important for correct type inference with isinstance.
-TypeRange = NamedTuple(
-    'TypeRange',
-    [
-        ('item', Type),
-        ('is_upper_bound', bool),  # False => precise type
-    ])
+class TypeRange(NamedTuple):
+    item: Type
+    is_upper_bound: bool  # False => precise type
+
 
 # Keeps track of partial types in a single scope. In fine-grained incremental
 # mode partial types initially defined at the top level cannot be completed in
 # a function, and we use the 'is_function' attribute to enforce this.
-PartialTypeScope = NamedTuple('PartialTypeScope', [('map', Dict[Var, Context]),
-                                                   ('is_function', bool),
-                                                   ('is_local', bool),
-                                                   ])
+class PartialTypeScope(NamedTuple):
+    map: Dict[Var, Context]
+    is_function: bool
+    is_local: bool
 
 
 class TypeChecker(NodeVisitor[None], CheckerPluginInterface):
@@ -891,7 +886,7 @@ def check_func_def(self, defn: FuncItem, typ: CallableType, name: Optional[str])
                                 self.msg.unimported_type_becomes_any("Return type", ret_type, fdef)
                             for idx, arg_type in enumerate(fdef.type.arg_types):
                                 if has_any_from_unimported_type(arg_type):
-                                    prefix = "Argument {} to \"{}\"".format(idx + 1, fdef.name)
+                                    prefix = f"Argument {idx + 1} to \"{fdef.name}\""
                                     self.msg.unimported_type_becomes_any(prefix, arg_type, fdef)
                     check_for_explicit_any(fdef.type, self.options, self.is_typeshed_stub,
                                            self.msg, context=fdef)
@@ -1062,9 +1057,9 @@ def check_default_args(self, item: FuncItem, body_is_trivial: bool) -> None:
             name = arg.variable.name
             msg = 'Incompatible default for '
             if name.startswith('__tuple_arg_'):
-                msg += "tuple argument {}".format(name[12:])
+                msg += f"tuple argument {name[12:]}"
             else:
-                msg += 'argument "{}"'.format(name)
+                msg += f'argument "{name}"'
             self.check_simple_assignment(
                 arg.variable.type,
                 arg.initializer,
@@ -1964,7 +1959,7 @@ def check_enum_bases(self, defn: ClassDef) -> None:
                 continue
             elif enum_base is not None:
                 self.fail(
-                    'No base classes are allowed after "{}"'.format(enum_base),
+                    f'No base classes are allowed after "{enum_base}"',
                     defn,
                 )
                 break
@@ -3308,8 +3303,8 @@ def check_simple_assignment(self, lvalue_type: Optional[Type], rvalue: Expressio
                 self.msg.deleted_as_lvalue(lvalue_type, context)
             elif lvalue_type:
                 self.check_subtype(rvalue_type, lvalue_type, context, msg,
-                                   '{} has type'.format(rvalue_name),
-                                   '{} has type'.format(lvalue_name), code=code)
+                                   f'{rvalue_name} has type',
+                                   f'{lvalue_name} has type', code=code)
             return rvalue_type
 
     def check_member_assignment(self, instance_type: Type, attribute_type: Type,
@@ -3717,7 +3712,7 @@ def _type_check_raise_python2(self, e: Expression, s: RaiseStmt, typ: ProperType
                 expected_type = TypeType(exc_type)
             self.check_subtype(
                 typ.items[0], expected_type, s,
-                'Argument 1 must be "{}" subtype'.format(expected_type),
+                f'Argument 1 must be "{expected_type}" subtype',
             )
 
             # Typecheck `traceback` part:
@@ -3732,7 +3727,7 @@ def _type_check_raise_python2(self, e: Expression, s: RaiseStmt, typ: ProperType
                 ])
                 self.check_subtype(
                     typ.items[2], traceback_type, s,
-                    'Argument 3 must be "{}" subtype'.format(traceback_type),
+                    f'Argument 3 must be "{traceback_type}" subtype',
                 )
         else:
             expected_type_items = [
@@ -4302,7 +4297,7 @@ def _make_fake_typeinfo_and_full_name(
                 curr_module_: MypyFile,
         ) -> Tuple[TypeInfo, str]:
             names_list = pretty_seq([x.type.name for x in base_classes_], "and")
-            short_name = '<subclass of {}>'.format(names_list)
+            short_name = f'<subclass of {names_list}>'
             full_name_ = gen_unique_name(short_name, curr_module_.names)
             cdef, info_ = self.make_fake_typeinfo(
                 curr_module_.fullname,
@@ -4354,7 +4349,7 @@ def intersect_instance_callable(self, typ: Instance, callable_type: CallableType
         # have a valid fullname and a corresponding entry in a symbol table. We generate
         # a unique name inside the symbol table of the current module.
         cur_module = cast(MypyFile, self.scope.stack[0])
-        gen_name = gen_unique_name("<callable subtype of {}>".format(typ.type.name),
+        gen_name = gen_unique_name(f"<callable subtype of {typ.type.name}>",
                                    cur_module.names)
 
         # Synthesize a fake TypeInfo
@@ -5367,7 +5362,7 @@ def lookup(self, name: str) -> SymbolTableNode:
                 table = cast(MypyFile, b.node).names
                 if name in table:
                     return table[name]
-            raise KeyError('Failed lookup: {}'.format(name))
+            raise KeyError(f'Failed lookup: {name}')
 
     def lookup_qualified(self, name: str) -> SymbolTableNode:
         if '.' not in name:
@@ -5891,7 +5886,7 @@ def and_conditional_maps(m1: TypeMap, m2: TypeMap) -> TypeMap:
     # arbitrarily give precedence to m2. (In the future, we could use
     # an intersection type.)
     result = m2.copy()
-    m2_keys = set(literal_hash(n2) for n2 in m2)
+    m2_keys = {literal_hash(n2) for n2 in m2}
     for n1 in m1:
         if literal_hash(n1) not in m2_keys:
             result[n1] = m1[n1]
@@ -6561,7 +6556,7 @@ def is_static(func: Union[FuncBase, Decorator]) -> bool:
         return is_static(func.func)
     elif isinstance(func, FuncBase):
         return func.is_static
-    assert False, "Unexpected func type: {}".format(type(func))
+    assert False, f"Unexpected func type: {type(func)}"
 
 
 def is_subtype_no_promote(left: Type, right: Type) -> bool:

mypy/checkexpr.py

@@ -156,7 +156,7 @@ def extract_refexpr_names(expr: RefExpr) -> Set[str]:
             else:
                 break
         else:
-            raise AssertionError("Unknown RefExpr subclass: {}".format(type(expr)))
+            raise AssertionError(f"Unknown RefExpr subclass: {type(expr)}")
     return output
 
 
@@ -437,7 +437,7 @@ def method_fullname(self, object_type: Type, method_name: str) -> Optional[str]:
             type_name = tuple_fallback(object_type).type.fullname
 
         if type_name is not None:
-            return '{}.{}'.format(type_name, method_name)
+            return f'{type_name}.{method_name}'
         else:
             return None
 
@@ -592,7 +592,7 @@ def check_typeddict_call_with_kwargs(self, callee: TypedDictType,
                 self.chk.check_simple_assignment(
                     lvalue_type=item_expected_type, rvalue=item_value, context=item_value,
                     msg=message_registry.INCOMPATIBLE_TYPES,
-                    lvalue_name='TypedDict item "{}"'.format(item_name),
+                    lvalue_name=f'TypedDict item "{item_name}"',
                     rvalue_name='expression',
                     code=codes.TYPEDDICT_ITEM)
 
@@ -2199,7 +2199,7 @@ def visit_op_expr(self, e: OpExpr) -> Type:
             e.method_type = method_type
             return result
         else:
-            raise RuntimeError('Unknown operator {}'.format(e.op))
+            raise RuntimeError(f'Unknown operator {e.op}')
 
     def visit_comparison_expr(self, e: ComparisonExpr) -> Type:
         """Type check a comparison expression.
@@ -2296,7 +2296,7 @@ def visit_comparison_expr(self, e: ComparisonExpr) -> Type:
                     self.msg.dangerous_comparison(left_type, right_type, 'identity', e)
                 method_type = None
             else:
-                raise RuntimeError('Unknown comparison operator {}'.format(operator))
+                raise RuntimeError(f'Unknown comparison operator {operator}')
 
             e.method_types.append(method_type)
 

mypy/checkmember.py

@@ -263,7 +263,7 @@ def analyze_type_callable_member_access(name: str,
         # Look up from the 'type' type.
         return _analyze_member_access(name, typ.fallback, mx)
     else:
-        assert False, 'Unexpected type {}'.format(repr(ret_type))
+        assert False, f'Unexpected type {ret_type!r}'
 
 
 def analyze_type_type_member_access(name: str,
@@ -410,7 +410,7 @@ def analyze_member_var_access(name: str,
                         result = getattr_type
 
                     # Call the attribute hook before returning.
-                    fullname = '{}.{}'.format(method.info.fullname, name)
+                    fullname = f'{method.info.fullname}.{name}'
                     hook = mx.chk.plugin.get_attribute_hook(fullname)
                     if hook:
                         result = hook(AttributeContext(get_proper_type(mx.original_type),
@@ -607,7 +607,7 @@ def analyze_var(name: str,
             mx.not_ready_callback(var.name, mx.context)
         # Implicit 'Any' type.
         result = AnyType(TypeOfAny.special_form)
-    fullname = '{}.{}'.format(var.info.fullname, name)
+    fullname = f'{var.info.fullname}.{name}'
     hook = mx.chk.plugin.get_attribute_hook(fullname)
     if result and not mx.is_lvalue and not implicit:
         result = analyze_descriptor_access(result, mx)

mypy/checkpattern.py

@@ -53,13 +53,10 @@
 # For every Pattern a PatternType can be calculated. This requires recursively calculating
 # the PatternTypes of the sub-patterns first.
 # Using the data in the PatternType the match subject and captured names can be narrowed/inferred.
-PatternType = NamedTuple(
-    'PatternType',
-    [
-        ('type', Type),  # The type the match subject can be narrowed to
-        ('rest_type', Type),  # The remaining type if the pattern didn't match
-        ('captures', Dict[Expression, Type]),  # The variables captured by the pattern
-    ])
+class PatternType(NamedTuple):
+    type: Type  # The type the match subject can be narrowed to
+    rest_type: Type  # The remaining type if the pattern didn't match
+    captures: Dict[Expression, Type]  # The variables captured by the pattern
 
 
 class PatternChecker(PatternVisitor[PatternType]):
@@ -628,7 +625,7 @@ def update_type_map(self,
                         ) -> None:
         # Calculating this would not be needed if TypeMap directly used literal hashes instead of
         # expressions, as suggested in the TODO above it's definition
-        already_captured = set(literal_hash(expr) for expr in original_type_map)
+        already_captured = {literal_hash(expr) for expr in original_type_map}
         for expr, typ in extra_type_map.items():
             if literal_hash(expr) in already_captured:
                 node = get_var(expr)

mypy/checkstrformat.py

@@ -519,7 +519,7 @@ def apply_field_accessors(self, spec: ConversionSpecifier, repl: Expression,
             dummy, fnam="<format>", module=None, options=self.chk.options, errors=temp_errors
         )
         if temp_errors.is_errors():
-            self.msg.fail('Syntax error in format specifier "{}"'.format(spec.field),
+            self.msg.fail(f'Syntax error in format specifier "{spec.field}"',
                           ctx, code=codes.STRING_FORMATTING)
             return TempNode(AnyType(TypeOfAny.from_error))