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prefect.utilities.dispatch

Provides methods for performing dynamic dispatch for actions on base type to one of its subtypes. Example: 
@register_base_type
class Base:
    @classmethod
    def __dispatch_key__(cls):
        return cls.__name__.lower()


class Foo(Base):
    ...

key = get_dispatch_key(Foo)  # 'foo'
lookup_type(Base, key) # Foo

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Functions

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get_registry_for_type 

get_registry_for_type(cls: T) -> Optional[dict[str, T]]
Get the first matching registry for a class or any of its base classes. If not found, None is returned.

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get_dispatch_key 

get_dispatch_key(cls_or_instance: Any, allow_missing: bool = False) -> Optional[str]
Retrieve the unique dispatch key for a class type or instance. This key is defined at the __dispatch_key__ attribute. If it is a callable, it will be resolved. If allow_missing is False, an exception will be raised if the attribute is not defined or the key is null. If True, None will be returned in these cases.

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register_base_type 

register_base_type(cls: T) -> T
Register a base type allowing child types to be registered for dispatch with register_type. The base class may or may not define a __dispatch_key__ to allow lookups of the base type.

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register_type 

register_type(cls: T) -> T
Register a type for lookup with dispatch. The type or one of its parents must define a unique __dispatch_key__. One of the classes base types must be registered using register_base_type.

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lookup_type 

lookup_type(cls: T, dispatch_key: str) -> T
Look up a dispatch key in the type registry for the given class.