diff options
Diffstat (limited to 'Lib/typing.py')
| -rw-r--r-- | Lib/typing.py | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/Lib/typing.py b/Lib/typing.py index 35deb32..29a3f43 100644 --- a/Lib/typing.py +++ b/Lib/typing.py @@ -2764,7 +2764,12 @@ _special = frozenset({'__module__', '__name__', '__annotations__'}) class NamedTupleMeta(type): def __new__(cls, typename, bases, ns): - assert bases[0] is _NamedTuple + assert _NamedTuple in bases + for base in bases: + if base is not _NamedTuple and base is not Generic: + raise TypeError( + 'can only inherit from a NamedTuple type and Generic') + bases = tuple(tuple if base is _NamedTuple else base for base in bases) types = ns.get('__annotations__', {}) default_names = [] for field_name in types: @@ -2778,12 +2783,18 @@ class NamedTupleMeta(type): nm_tpl = _make_nmtuple(typename, types.items(), defaults=[ns[n] for n in default_names], module=ns['__module__']) + nm_tpl.__bases__ = bases + if Generic in bases: + class_getitem = Generic.__class_getitem__.__func__ + nm_tpl.__class_getitem__ = classmethod(class_getitem) # update from user namespace without overriding special namedtuple attributes for key in ns: if key in _prohibited: raise AttributeError("Cannot overwrite NamedTuple attribute " + key) elif key not in _special and key not in nm_tpl._fields: setattr(nm_tpl, key, ns[key]) + if Generic in bases: + nm_tpl.__init_subclass__() return nm_tpl @@ -2821,9 +2832,7 @@ def NamedTuple(typename, fields=None, /, **kwargs): _NamedTuple = type.__new__(NamedTupleMeta, 'NamedTuple', (), {}) def _namedtuple_mro_entries(bases): - if len(bases) > 1: - raise TypeError("Multiple inheritance with NamedTuple is not supported") - assert bases[0] is NamedTuple + assert NamedTuple in bases return (_NamedTuple,) NamedTuple.__mro_entries__ = _namedtuple_mro_entries |