Python MessageBuilder.cant_assign_to_method方法代码示例

# 需要导入模块: from mypy.messages import MessageBuilder [as 别名]
# 或者: from mypy.messages.MessageBuilder import cant_assign_to_method [as 别名]
def analyze_class_attribute_access(itype: Instance,
                                   name: str,
                                   context: Context,
                                   is_lvalue: bool,
                                   builtin_type: Callable[[str], Instance],
                                   msg: MessageBuilder) -> Type:
    node = itype.type.get(name)
    if not node:
        return None

    is_decorated = isinstance(node.node, Decorator)
    is_method = is_decorated or isinstance(node.node, FuncDef)
    if is_lvalue:
        if is_method:
            msg.cant_assign_to_method(context)
        if isinstance(node.node, TypeInfo):
            msg.fail(messages.CANNOT_ASSIGN_TO_TYPE, context)

    if itype.type.is_enum and not (is_lvalue or is_decorated or is_method):
        return itype

    t = node.type
    if t:
        is_classmethod = is_decorated and cast(Decorator, node.node).func.is_class
        return add_class_tvars(t, itype.type, is_classmethod, builtin_type)

    if isinstance(node.node, TypeInfo):
        return type_object_type(cast(TypeInfo, node.node), builtin_type)

    return function_type(cast(FuncBase, node.node), builtin_type('builtins.function'))

# 需要导入模块: from mypy.messages import MessageBuilder [as 别名]
# 或者: from mypy.messages.MessageBuilder import cant_assign_to_method [as 别名]
def analyse_class_attribute_access(itype: Instance, name: str,
                                   context: Context, is_lvalue: bool,
                                   msg: MessageBuilder) -> Type:
    node = itype.type.get(name)
    if not node:
        return None

    is_decorated = isinstance(node.node, Decorator)
    is_method = is_decorated or isinstance(node.node, FuncDef)
    if is_lvalue:
        if is_method:
            msg.cant_assign_to_method(context)
        if isinstance(node.node, TypeInfo):
            msg.fail(messages.CANNOT_ASSIGN_TO_TYPE, context)

    t = node.type
    if t:
        is_classmethod = is_decorated and cast(Decorator, node.node).func.is_class
        return add_class_tvars(t, itype.type, is_classmethod)

    if isinstance(node.node, TypeInfo):
        # TODO add second argument
        return type_object_type(cast(TypeInfo, node.node), None)

    return function_type(cast(FuncBase, node.node))

# 需要导入模块: from mypy.messages import MessageBuilder [as 别名]
# 或者: from mypy.messages.MessageBuilder import cant_assign_to_method [as 别名]
def analyse_member_var_access(name: str, itype: Instance, info: TypeInfo,
                              node: Context, is_lvalue: bool, is_super: bool,
                              msg: MessageBuilder,
                              report_type: Type = None) -> Type:
    """Analyse attribute access that does not target a method.

    This is logically part of analyse_member_access and the arguments are
    similar.
    """
    # It was not a method. Try looking up a variable.
    v = lookup_member_var_or_accessor(info, name, is_lvalue)

    vv = v
    if isinstance(vv, Decorator):
        # The associated Var node of a decorator contains the type.
        v = vv.var

    if isinstance(v, Var):
        # Found a member variable.
        var = v
        itype = map_instance_to_supertype(itype, var.info)
        if var.type:
            t = expand_type_by_instance(var.type, itype)
            if var.is_initialized_in_class and isinstance(t, FunctionLike):
                if is_lvalue:
                    if var.is_property:
                        msg.read_only_property(name, info, node)
                    else:
                        msg.cant_assign_to_method(node)

                if not var.is_staticmethod:
                    # Class-level function objects and classmethods become bound
                    # methods: the former to the instance, the latter to the
                    # class.
                    functype = cast(FunctionLike, t)
                    check_method_type(functype, itype, node, msg)
                    signature = method_type(functype)
                    if var.is_property:
                        # A property cannot have an overloaded type => the cast
                        # is fine.
                        return cast(Callable, signature).ret_type
                    else:
                        return signature
            return t
        else:
            if not var.is_ready:
                msg.cannot_determine_type(var.name(), node)
            # Implicit 'Any' type.
            return AnyType()
    elif isinstance(v, FuncDef):
        assert False, "Did not expect a function"

    # Could not find the member.
    if is_super:
        msg.undefined_in_superclass(name, node)
        return AnyType()
    else:
        return msg.has_no_attr(report_type or itype, name, node)

# 需要导入模块: from mypy.messages import MessageBuilder [as 别名]
# 或者: from mypy.messages.MessageBuilder import cant_assign_to_method [as 别名]
def analyze_class_attribute_access(itype: Instance,
                                   name: str,
                                   context: Context,
                                   is_lvalue: bool,
                                   builtin_type: Callable[[str], Instance],
                                   not_ready_callback: Callable[[str, Context], None],
                                   msg: MessageBuilder,
                                   original_type: Type) -> Optional[Type]:
    """original_type is the type of E in the expression E.var"""
    node = itype.type.get(name)
    if not node:
        if itype.type.fallback_to_any:
            return AnyType(TypeOfAny.special_form)
        return None

    is_decorated = isinstance(node.node, Decorator)
    is_method = is_decorated or isinstance(node.node, FuncDef)
    if is_lvalue:
        if is_method:
            msg.cant_assign_to_method(context)
        if isinstance(node.node, TypeInfo):
            msg.fail(messages.CANNOT_ASSIGN_TO_TYPE, context)

    if itype.type.is_enum and not (is_lvalue or is_decorated or is_method):
        return itype

    t = node.type
    if t:
        if isinstance(t, PartialType):
            symnode = node.node
            assert symnode is not None
            return handle_partial_attribute_type(t, is_lvalue, msg, symnode)
        if not is_method and (isinstance(t, TypeVarType) or get_type_vars(t)):
            msg.fail(messages.GENERIC_INSTANCE_VAR_CLASS_ACCESS, context)
        is_classmethod = is_decorated and cast(Decorator, node.node).func.is_class
        return add_class_tvars(t, itype, is_classmethod, builtin_type, original_type)
    elif isinstance(node.node, Var):
        not_ready_callback(name, context)
        return AnyType(TypeOfAny.special_form)

    if isinstance(node.node, TypeVarExpr):
        msg.fail('Type variable "{}.{}" cannot be used as an expression'.format(
                 itype.type.name(), name), context)
        return AnyType(TypeOfAny.from_error)

    if isinstance(node.node, TypeInfo):
        return type_object_type(node.node, builtin_type)

    if isinstance(node.node, MypyFile):
        # Reference to a module object.
        return builtin_type('types.ModuleType')

    if is_decorated:
        # TODO: Return type of decorated function. This is quick hack to work around #998.
        return AnyType(TypeOfAny.special_form)
    else:
        return function_type(cast(FuncBase, node.node), builtin_type('builtins.function'))

# 需要导入模块: from mypy.messages import MessageBuilder [as 别名]
# 或者: from mypy.messages.MessageBuilder import cant_assign_to_method [as 别名]
def analyze_var(
    name: str,
    var: Var,
    itype: Instance,
    info: TypeInfo,
    node: Context,
    is_lvalue: bool,
    msg: MessageBuilder,
    not_ready_callback: Callable[[str, Context], None],
) -> Type:
    """Analyze access to an attribute via a Var node.

    This is conceptually part of analyze_member_access and the arguments are similar.
    """
    # Found a member variable.
    itype = map_instance_to_supertype(itype, var.info)
    typ = var.type
    if typ:
        if isinstance(typ, PartialType):
            return handle_partial_attribute_type(typ, is_lvalue, msg, var)
        t = expand_type_by_instance(typ, itype)
        if is_lvalue and var.is_property and not var.is_settable_property:
            # TODO allow setting attributes in subclass (although it is probably an error)
            msg.read_only_property(name, info, node)
        if var.is_initialized_in_class and isinstance(t, FunctionLike):
            if is_lvalue:
                if var.is_property:
                    if not var.is_settable_property:
                        msg.read_only_property(name, info, node)
                else:
                    msg.cant_assign_to_method(node)

            if not var.is_staticmethod:
                # Class-level function objects and classmethods become bound
                # methods: the former to the instance, the latter to the
                # class.
                functype = t
                check_method_type(functype, itype, var.is_classmethod, node, msg)
                signature = method_type(functype)
                if var.is_property:
                    # A property cannot have an overloaded type => the cast
                    # is fine.
                    return cast(CallableType, signature).ret_type
                else:
                    return signature
        return t
    else:
        if not var.is_ready:
            not_ready_callback(var.name(), node)
        # Implicit 'Any' type.
        return AnyType()

# 需要导入模块: from mypy.messages import MessageBuilder [as 别名]
# 或者: from mypy.messages.MessageBuilder import cant_assign_to_method [as 别名]
def analyze_class_attribute_access(itype: Instance,
                                   name: str,
                                   context: Context,
                                   is_lvalue: bool,
                                   builtin_type: Callable[[str], Instance],
                                   not_ready_callback: Callable[[str, Context], None],
                                   msg: MessageBuilder,
                                   original_type: Type) -> Type:
    """original_type is the type of E in the expression E.var"""
    node = itype.type.get(name)
    if not node:
        if itype.type.fallback_to_any:
            return AnyType()
        return None

    is_decorated = isinstance(node.node, Decorator)
    is_method = is_decorated or isinstance(node.node, FuncDef)
    if is_lvalue:
        if is_method:
            msg.cant_assign_to_method(context)
        if isinstance(node.node, TypeInfo):
            msg.fail(messages.CANNOT_ASSIGN_TO_TYPE, context)

    if itype.type.is_enum and not (is_lvalue or is_decorated or is_method):
        return itype

    t = node.type
    if t:
        if isinstance(t, PartialType):
            return handle_partial_attribute_type(t, is_lvalue, msg, node.node)
        is_classmethod = is_decorated and cast(Decorator, node.node).func.is_class
        return add_class_tvars(t, itype, is_classmethod, builtin_type, original_type)
    elif isinstance(node.node, Var):
        not_ready_callback(name, context)
        return AnyType()

    if isinstance(node.node, TypeVarExpr):
        return TypeVarType(node.tvar_def, node.tvar_def.line, node.tvar_def.column)

    if isinstance(node.node, TypeInfo):
        return type_object_type(node.node, builtin_type)

    if isinstance(node.node, MypyFile):
        # Reference to a module object.
        return builtin_type('builtins.module')

    if is_decorated:
        # TODO: Return type of decorated function. This is quick hack to work around #998.
        return AnyType()
    else:
        return function_type(cast(FuncBase, node.node), builtin_type('builtins.function'))

# 需要导入模块: from mypy.messages import MessageBuilder [as 别名]
# 或者: from mypy.messages.MessageBuilder import cant_assign_to_method [as 别名]
def analyze_class_attribute_access(
    itype: Instance,
    name: str,
    context: Context,
    is_lvalue: bool,
    builtin_type: Callable[[str], Instance],
    not_ready_callback: Callable[[str, Context], None],
    msg: MessageBuilder,
) -> Type:
    node = itype.type.get(name)
    if not node:
        if itype.type.fallback_to_any:
            return AnyType()
        return None

    is_decorated = isinstance(node.node, Decorator)
    is_method = is_decorated or isinstance(node.node, FuncDef)
    if is_lvalue:
        if is_method:
            msg.cant_assign_to_method(context)
        if isinstance(node.node, TypeInfo):
            msg.fail(messages.CANNOT_ASSIGN_TO_TYPE, context)

    if itype.type.is_enum and not (is_lvalue or is_decorated or is_method):
        return itype

    t = node.type
    if t:
        is_classmethod = is_decorated and cast(Decorator, node.node).func.is_class
        return add_class_tvars(t, itype.type, is_classmethod, builtin_type)
    elif isinstance(node.node, Var):
        not_ready_callback(name, context)
        return AnyType()

    if isinstance(node.node, TypeInfo):
        return type_object_type(cast(TypeInfo, node.node), builtin_type)

    if is_decorated:
        # TODO: Return type of decorated function. This is quick hack to work around #998.
        return AnyType()
    else:
        return function_type(cast(FuncBase, node.node), builtin_type("builtins.function"))

# 需要导入模块: from mypy.messages import MessageBuilder [as 别名]
# 或者: from mypy.messages.MessageBuilder import cant_assign_to_method [as 别名]
def analyze_var(
    name: str, var: Var, itype: Instance, info: TypeInfo, node: Context, is_lvalue: bool, msg: MessageBuilder
) -> Type:
    """Analyze access to an attribute via a Var node.

    This is conceptually part of analyze_member_access and the arguments are similar.
    """
    # Found a member variable.
    itype = map_instance_to_supertype(itype, var.info)
    if var.type:
        t = expand_type_by_instance(var.type, itype)
        if var.is_initialized_in_class and isinstance(t, FunctionLike):
            if is_lvalue:
                if var.is_property:
                    if not var.is_settable_property:
                        msg.read_only_property(name, info, node)
                else:
                    msg.cant_assign_to_method(node)

            if not var.is_staticmethod:
                # Class-level function objects and classmethods become bound
                # methods: the former to the instance, the latter to the
                # class.
                functype = cast(FunctionLike, t)
                check_method_type(functype, itype, node, msg)
                signature = method_type(functype)
                if var.is_property:
                    # A property cannot have an overloaded type => the cast
                    # is fine.
                    return cast(CallableType, signature).ret_type
                else:
                    return signature
        return t
    else:
        if not var.is_ready:
            msg.cannot_determine_type(var.name(), node)
        # Implicit 'Any' type.
        return AnyType()

# 需要导入模块: from mypy.messages import MessageBuilder [as 别名]
# 或者: from mypy.messages.MessageBuilder import cant_assign_to_method [as 别名]
def analyze_member_access(
    name: str,
    typ: Type,
    node: Context,
    is_lvalue: bool,
    is_super: bool,
    is_operator: bool,
    builtin_type: Callable[[str], Instance],
    not_ready_callback: Callable[[str, Context], None],
    msg: MessageBuilder,
    override_info: TypeInfo = None,
    report_type: Type = None,
    chk: "mypy.checker.TypeChecker" = None,
) -> Type:
    """Analyse attribute access.

    This is a general operation that supports various different variations:

      1. lvalue or non-lvalue access (i.e. setter or getter access)
      2. supertype access (when using super(); is_super == True and
         override_info should refer to the supertype)
    """
    report_type = report_type or typ
    if isinstance(typ, Instance):
        if name == "__init__" and not is_super:
            # Accessing __init__ in statically typed code would compromise
            # type safety unless used via super().
            msg.fail(messages.CANNOT_ACCESS_INIT, node)
            return AnyType()

        # The base object has an instance type.

        info = typ.type
        if override_info:
            info = override_info

        # Look up the member. First look up the method dictionary.
        method = info.get_method(name)
        if method:
            if method.is_property:
                assert isinstance(method, OverloadedFuncDef)
                return analyze_var(name, method.items[0].var, typ, info, node, is_lvalue, msg, not_ready_callback)
            if is_lvalue:
                msg.cant_assign_to_method(node)
            typ = map_instance_to_supertype(typ, method.info)
            if name == "__new__":
                # __new__ is special and behaves like a static method -- don't strip
                # the first argument.
                signature = function_type(method, builtin_type("builtins.function"))
            else:
                signature = method_type_with_fallback(method, builtin_type("builtins.function"))
            return expand_type_by_instance(signature, typ)
        else:
            # Not a method.
            return analyze_member_var_access(
                name,
                typ,
                info,
                node,
                is_lvalue,
                is_super,
                builtin_type,
                not_ready_callback,
                msg,
                report_type=report_type,
                chk=chk,
            )
    elif isinstance(typ, AnyType):
        # The base object has dynamic type.
        return AnyType()
    elif isinstance(typ, NoneTyp):
        if chk and chk.should_suppress_optional_error([typ]):
            return AnyType()
        # The only attribute NoneType has are those it inherits from object
        return analyze_member_access(
            name,
            builtin_type("builtins.object"),
            node,
            is_lvalue,
            is_super,
            is_operator,
            builtin_type,
            not_ready_callback,
            msg,
            report_type=report_type,
            chk=chk,
        )
    elif isinstance(typ, UnionType):
        # The base object has dynamic type.
        msg.disable_type_names += 1
        results = [
            analyze_member_access(
                name, subtype, node, is_lvalue, is_super, is_operator, builtin_type, not_ready_callback, msg, chk=chk
            )
            for subtype in typ.items
        ]
        msg.disable_type_names -= 1
        return UnionType.make_simplified_union(results)
    elif isinstance(typ, TupleType):
        # Actually look up from the fallback instance type.
#.........这里部分代码省略.........

# 需要导入模块: from mypy.messages import MessageBuilder [as 别名]
# 或者: from mypy.messages.MessageBuilder import cant_assign_to_method [as 别名]
def analyze_member_access(name: str, typ: Type, node: Context, is_lvalue: bool,
                          is_super: bool,
                          builtin_type: Callable[[str], Instance],
                          not_ready_callback: Callable[[str, Context], None],
                          msg: MessageBuilder, override_info: TypeInfo = None,
                          report_type: Type = None) -> Type:
    """Analyse attribute access.

    This is a general operation that supports various different variations:

      1. lvalue or non-lvalue access (i.e. setter or getter access)
      2. supertype access (when using super(); is_super == True and
         override_info should refer to the supertype)
    """
    report_type = report_type or typ
    if isinstance(typ, Instance):
        if name == '__init__' and not is_super:
            # Accessing __init__ in statically typed code would compromise
            # type safety unless used via super().
            msg.fail(messages.CANNOT_ACCESS_INIT, node)
            return AnyType()

        # The base object has an instance type.

        info = typ.type
        if override_info:
            info = override_info

        # Look up the member. First look up the method dictionary.
        method = info.get_method(name)
        if method:
            if method.is_property:
                assert isinstance(method, OverloadedFuncDef)
                method = cast(OverloadedFuncDef, method)
                return analyze_var(name, method.items[0].var, typ, info, node, is_lvalue, msg,
                                   not_ready_callback)
            if is_lvalue:
                msg.cant_assign_to_method(node)
            typ = map_instance_to_supertype(typ, method.info)
            if name == '__new__':
                # __new__ is special and behaves like a static method -- don't strip
                # the first argument.
                signature = function_type(method, builtin_type('builtins.function'))
            else:
                signature = method_type_with_fallback(method, builtin_type('builtins.function'))
            return expand_type_by_instance(signature, typ)
        else:
            # Not a method.
            return analyze_member_var_access(name, typ, info, node,
                                             is_lvalue, is_super, builtin_type,
                                             not_ready_callback, msg,
                                             report_type=report_type)
    elif isinstance(typ, AnyType):
        # The base object has dynamic type.
        return AnyType()
    elif isinstance(typ, UnionType):
        # The base object has dynamic type.
        msg.disable_type_names += 1
        results = [analyze_member_access(name, subtype, node, is_lvalue,
                                         is_super, builtin_type, not_ready_callback, msg)
                   for subtype in typ.items]
        msg.disable_type_names -= 1
        return UnionType.make_simplified_union(results)
    elif isinstance(typ, TupleType):
        # Actually look up from the fallback instance type.
        return analyze_member_access(name, typ.fallback, node, is_lvalue,
                                     is_super, builtin_type, not_ready_callback, msg)
    elif isinstance(typ, FunctionLike) and typ.is_type_obj():
        # Class attribute.
        # TODO super?
        ret_type = typ.items()[0].ret_type
        if isinstance(ret_type, TupleType):
            ret_type = ret_type.fallback
        if isinstance(ret_type, Instance):
            result = analyze_class_attribute_access(ret_type, name, node, is_lvalue,
                                                    builtin_type, not_ready_callback, msg)
            if result:
                return result
            # Look up from the 'type' type.
            return analyze_member_access(name, typ.fallback, node, is_lvalue, is_super,
                                         builtin_type, not_ready_callback, msg,
                                         report_type=report_type)
        else:
            assert False, 'Unexpected type {}'.format(repr(ret_type))
    elif isinstance(typ, FunctionLike):
        # Look up from the 'function' type.
        return analyze_member_access(name, typ.fallback, node, is_lvalue, is_super,
                                     builtin_type, not_ready_callback, msg,
                                     report_type=report_type)
    elif isinstance(typ, TypeVarType):
        return analyze_member_access(name, typ.upper_bound, node, is_lvalue, is_super,
                                     builtin_type, not_ready_callback, msg,
                                     report_type=report_type)
    elif isinstance(typ, DeletedType):
        msg.deleted_as_rvalue(typ, node)
        return AnyType()
    return msg.has_no_attr(report_type, name, node)

# 需要导入模块: from mypy.messages import MessageBuilder [as 别名]
# 或者: from mypy.messages.MessageBuilder import cant_assign_to_method [as 别名]
def analyze_member_access(name: str,
                          typ: Type,
                          node: Context,
                          is_lvalue: bool,
                          is_super: bool,
                          is_operator: bool,
                          builtin_type: Callable[[str], Instance],
                          not_ready_callback: Callable[[str, Context], None],
                          msg: MessageBuilder, *,
                          original_type: Type,
                          chk: 'mypy.checker.TypeChecker',
                          override_info: Optional[TypeInfo] = None) -> Type:
    """Return the type of attribute `name` of typ.

    This is a general operation that supports various different variations:

      1. lvalue or non-lvalue access (i.e. setter or getter access)
      2. supertype access (when using super(); is_super == True and
         override_info should refer to the supertype)

    original_type is the most precise inferred or declared type of the base object
    that we have available. typ is generally a supertype of original_type.
    When looking for an attribute of typ, we may perform recursive calls targeting
    the fallback type, for example.
    original_type is always the type used in the initial call.
    """
    # TODO: this and following functions share some logic with subtypes.find_member,
    # consider refactoring.
    if isinstance(typ, Instance):
        if name == '__init__' and not is_super:
            # Accessing __init__ in statically typed code would compromise
            # type safety unless used via super().
            msg.fail(messages.CANNOT_ACCESS_INIT, node)
            return AnyType(TypeOfAny.from_error)

        # The base object has an instance type.

        info = typ.type
        if override_info:
            info = override_info

        if (experiments.find_occurrences and
                info.name() == experiments.find_occurrences[0] and
                name == experiments.find_occurrences[1]):
            msg.note("Occurrence of '{}.{}'".format(*experiments.find_occurrences), node)

        # Look up the member. First look up the method dictionary.
        method = info.get_method(name)
        if method:
            if method.is_property:
                assert isinstance(method, OverloadedFuncDef)
                first_item = cast(Decorator, method.items[0])
                return analyze_var(name, first_item.var, typ, info, node, is_lvalue, msg,
                                   original_type, not_ready_callback, chk=chk)
            if is_lvalue:
                msg.cant_assign_to_method(node)
            signature = function_type(method, builtin_type('builtins.function'))
            signature = freshen_function_type_vars(signature)
            if name == '__new__':
                # __new__ is special and behaves like a static method -- don't strip
                # the first argument.
                pass
            else:
                signature = bind_self(signature, original_type)
            typ = map_instance_to_supertype(typ, method.info)
            member_type = expand_type_by_instance(signature, typ)
            freeze_type_vars(member_type)
            return member_type
        else:
            # Not a method.
            return analyze_member_var_access(name, typ, info, node,
                                             is_lvalue, is_super, builtin_type,
                                             not_ready_callback, msg,
                                             original_type=original_type, chk=chk)
    elif isinstance(typ, AnyType):
        # The base object has dynamic type.
        return AnyType(TypeOfAny.from_another_any, source_any=typ)
    elif isinstance(typ, NoneTyp):
        if chk.should_suppress_optional_error([typ]):
            return AnyType(TypeOfAny.from_error)
        # The only attribute NoneType has are those it inherits from object
        return analyze_member_access(name, builtin_type('builtins.object'), node, is_lvalue,
                                     is_super, is_operator, builtin_type, not_ready_callback, msg,
                                     original_type=original_type, chk=chk)
    elif isinstance(typ, UnionType):
        # The base object has dynamic type.
        msg.disable_type_names += 1
        results = [analyze_member_access(name, subtype, node, is_lvalue, is_super,
                                         is_operator, builtin_type, not_ready_callback, msg,
                                         original_type=original_type, chk=chk)
                   for subtype in typ.relevant_items()]
        msg.disable_type_names -= 1
        return UnionType.make_simplified_union(results)
    elif isinstance(typ, TupleType):
        # Actually look up from the fallback instance type.
        return analyze_member_access(name, typ.fallback, node, is_lvalue, is_super,
                                     is_operator, builtin_type, not_ready_callback, msg,
                                     original_type=original_type, chk=chk)
    elif isinstance(typ, TypedDictType):
        # Actually look up from the fallback instance type.
#.........这里部分代码省略.........

# 需要导入模块: from mypy.messages import MessageBuilder [as 别名]
# 或者: from mypy.messages.MessageBuilder import cant_assign_to_method [as 别名]
def analyze_var(name: str, var: Var, itype: Instance, info: TypeInfo, node: Context,
                is_lvalue: bool, msg: MessageBuilder, original_type: Type,
                not_ready_callback: Callable[[str, Context], None], *,
                chk: 'mypy.checker.TypeChecker') -> Type:
    """Analyze access to an attribute via a Var node.

    This is conceptually part of analyze_member_access and the arguments are similar.

    itype is the class object in which var is dedined
    original_type is the type of E in the expression E.var
    """
    # Found a member variable.
    itype = map_instance_to_supertype(itype, var.info)
    typ = var.type
    if typ:
        if isinstance(typ, PartialType):
            return handle_partial_attribute_type(typ, is_lvalue, msg, var)
        t = expand_type_by_instance(typ, itype)
        if is_lvalue and var.is_property and not var.is_settable_property:
            # TODO allow setting attributes in subclass (although it is probably an error)
            msg.read_only_property(name, info, node)
        if is_lvalue and var.is_classvar:
            msg.cant_assign_to_classvar(name, node)
        result = t
        if var.is_initialized_in_class and isinstance(t, FunctionLike) and not t.is_type_obj():
            if is_lvalue:
                if var.is_property:
                    if not var.is_settable_property:
                        msg.read_only_property(name, info, node)
                else:
                    msg.cant_assign_to_method(node)

            if not var.is_staticmethod:
                # Class-level function objects and classmethods become bound methods:
                # the former to the instance, the latter to the class.
                functype = t
                # Use meet to narrow original_type to the dispatched type.
                # For example, assume
                # * A.f: Callable[[A1], None] where A1 <: A (maybe A1 == A)
                # * B.f: Callable[[B1], None] where B1 <: B (maybe B1 == B)
                # * x: Union[A1, B1]
                # In `x.f`, when checking `x` against A1 we assume x is compatible with A
                # and similarly for B1 when checking agains B
                dispatched_type = meet.meet_types(original_type, itype)
                check_self_arg(functype, dispatched_type, var.is_classmethod, node, name, msg)
                signature = bind_self(functype, original_type, var.is_classmethod)
                if var.is_property:
                    # A property cannot have an overloaded type => the cast is fine.
                    assert isinstance(signature, CallableType)
                    result = signature.ret_type
                else:
                    result = signature
    else:
        if not var.is_ready:
            not_ready_callback(var.name(), node)
        # Implicit 'Any' type.
        result = AnyType(TypeOfAny.special_form)
    fullname = '{}.{}'.format(var.info.fullname(), name)
    hook = chk.plugin.get_attribute_hook(fullname)
    if hook:
        result = hook(AttributeContext(original_type, result, node, chk))
    return result

# 需要导入模块: from mypy.messages import MessageBuilder [as 别名]
# 或者: from mypy.messages.MessageBuilder import cant_assign_to_method [as 别名]
def analyse_member_access(name: str, typ: Type, node: Context, is_lvalue: bool,
                          is_super: bool,
                          builtin_type: Function[[str], Instance],
                          msg: MessageBuilder, override_info: TypeInfo = None,
                          report_type: Type = None) -> Type:
    """Analyse attribute access.

    This is a general operation that supports various different variations:

      1. lvalue or non-lvalue access (i.e. setter or getter access)
      2. supertype access (when using super(); is_super == True and
         override_info should refer to the supertype)
    """
    report_type = report_type or typ
    if isinstance(typ, Instance):
        if name == '__init__' and not is_super:
            # Accessing __init__ in statically typed code would compromise
            # type safety unless used via super().
            msg.fail(messages.CANNOT_ACCESS_INIT, node)
            return AnyType()

        # The base object has an instance type.

        info = typ.type
        if override_info:
            info = override_info

        # Look up the member. First look up the method dictionary.
        method = info.get_method(name)
        if method:
            if is_lvalue:
                msg.cant_assign_to_method(node)
            typ = map_instance_to_supertype(typ, method.info)
            return expand_type_by_instance(
                method_type(method, builtin_type('builtins.function')), typ)
        else:
            # Not a method.
            return analyse_member_var_access(name, typ, info, node,
                                             is_lvalue, is_super, msg,
                                             report_type=report_type)
    elif isinstance(typ, AnyType):
        # The base object has dynamic type.
        return AnyType()
    elif isinstance(typ, UnionType):
        # The base object has dynamic type.
        msg.disable_type_names += 1
        results = [analyse_member_access(name, subtype, node, is_lvalue,
                                         is_super, builtin_type, msg)
                   for subtype in typ.items]
        msg.disable_type_names -= 1
        return UnionType.make_simplified_union(results)
    elif isinstance(typ, TupleType):
        # Actually look up from the fallback instance type.
        return analyse_member_access(name, typ.fallback, node, is_lvalue,
                                     is_super, builtin_type, msg)
    elif (isinstance(typ, FunctionLike) and
          cast(FunctionLike, typ).is_type_obj()):
        # Class attribute.
        # TODO super?
        sig = cast(FunctionLike, typ)
        itype = cast(Instance, sig.items()[0].ret_type)
        result = analyse_class_attribute_access(itype, name, node, is_lvalue, builtin_type, msg)
        if result:
            return result
        # Look up from the 'type' type.
        return analyse_member_access(name, sig.fallback, node, is_lvalue, is_super,
                                     builtin_type, msg, report_type=report_type)
    elif isinstance(typ, FunctionLike):
        # Look up from the 'function' type.
        return analyse_member_access(name, typ.fallback, node, is_lvalue, is_super,
                                     builtin_type, msg, report_type=report_type)
    return msg.has_no_attr(report_type, name, node)