Kelas dasar abstrak untuk tipe generik.
class typing.Generic
class Mapping(Generic[KT, VT]):
def __getitem__(self, key: KT) -> VT:
...
Etc.
X = TypeVar('X')
Y = TypeVar('Y')
def lookup_name(mapping: Mapping[X, Y], key: X, default: Y) -> Y:
try:
return mapping[key]
except KeyError:
return default