| 33 | _abc_invalidation_counter = 0 |
| 34 | |
| 35 | def __new__(mcls, name, bases, namespace, /, **kwargs): |
| 36 | cls = super().__new__(mcls, name, bases, namespace, **kwargs) |
| 37 | # Compute set of abstract method names |
| 38 | abstracts = {name |
| 39 | for name, value in namespace.items() |
| 40 | if getattr(value, "__isabstractmethod__", False)} |
| 41 | for base in bases: |
| 42 | for name in getattr(base, "__abstractmethods__", set()): |
| 43 | value = getattr(cls, name, None) |
| 44 | if getattr(value, "__isabstractmethod__", False): |
| 45 | abstracts.add(name) |
| 46 | cls.__abstractmethods__ = frozenset(abstracts) |
| 47 | # Set up inheritance registry |
| 48 | cls._abc_registry = WeakSet() |
| 49 | cls._abc_cache = WeakSet() |
| 50 | cls._abc_negative_cache = WeakSet() |
| 51 | cls._abc_negative_cache_version = ABCMeta._abc_invalidation_counter |
| 52 | return cls |
| 53 | |
| 54 | def register(cls, subclass): |
| 55 | """Register a virtual subclass of an ABC. |