S3Generic

S3Generic(name, default=None, doc='')

A callable that dispatches to a registered method based on the type of its first argument, with a user-supplied default fallback.

Parameters

Name	Type	Description	Default
name	str	The name of the generic (used in error messages).	required
default	callable	Default implementation called when no specific method is registered for the argument’s type. Receives (obj, *args, **kwargs).	None
doc	str	Docstring appended to the auto-generated signature line.	''

Examples

>>> from s3generics import S3Generic
>>> summary = S3Generic("summary")
>>>
>>> @summary.register(list)
... def _summary_list(obj, *args, **kwargs):
...     print(f"list of length {len(obj)}")
>>>
>>> summary([1, 2, 3])
list of length 3

Methods

Name	Description
dispatch	Return the best-matching method for obj without calling it.
methods	Return {type_name: callable} for all registered methods.
register	Decorator that registers a method for one or more types.
register_for	Imperative (non-decorator) registration.

dispatch

S3Generic.dispatch(obj)

Return the best-matching method for obj without calling it.

methods

S3Generic.methods()

Return {type_name: callable} for all registered methods.

register

S3Generic.register(*types)

Decorator that registers a method for one or more types.

from s3generics import S3Generic summary = S3Generic(“summary”)

class MyClass: … def init(self, data): … self.data = data … @summary.register(MyClass) … def _summary_myclass(obj, **kw): …

register_for

S3Generic.register_for(fn, *types)

Imperative (non-decorator) registration.