# typing.Protocol - pydoc - phpman

Help on class Protocol in typing:

typing.Protocol = class Protocol(Generic)
 |  Base class for protocol classes.
 |
 |  Protocol classes are defined as::
 |
 |      class Proto(Protocol):
 |          def meth(self) -> int:
 |              ...
 |
 |  Such classes are primarily used with static type checkers that recognize
 |  structural subtyping (static duck-typing), for example::
 |
 |      class C:
 |          def meth(self) -> int:
 |              return 0
 |
 |      def func(x: Proto) -> int:
 |          return x.meth()
 |
 |      func(C())  # Passes static type check
 |
 |  See PEP 544 for details. Protocol classes decorated with
 |  @typing.runtime_checkable act as simple-minded runtime protocols that check
 |  only the presence of given attributes, ignoring their type signatures.
 |  Protocol classes can be generic, they are defined as::
 |
 |      class GenProto(Protocol[T]):
 |          def meth(self) -> T:
 |              ...
 |
 |  Method resolution order:
 |      Protocol
 |      Generic
 |      builtins.object
 |
 |  Class methods defined here:
 |
 |  __init_subclass__(*args, **kwargs) from typing._ProtocolMeta
 |      This method is called when a class is subclassed.
 |
 |      The default implementation does nothing. It may be
 |      overridden to extend subclasses.
 |
 |  ----------------------------------------------------------------------
 |  Data and other attributes defined here:
 |
 |  __abstractmethods__ = frozenset()
 |
 |  __parameters__ = ()
 |
 |  ----------------------------------------------------------------------
 |  Class methods inherited from Generic:
 |
 |  __class_getitem__(params) from typing._ProtocolMeta