import logging from typing import Callable, Iterable, List, Optional, Type, Union from ray.rllib.agents.trainer import Trainer, COMMON_CONFIG from ray.rllib.env.env_context import EnvContext from ray.rllib.evaluation.worker_set import WorkerSet from ray.rllib.policy import Policy from ray.rllib.utils import add_mixins from ray.rllib.utils.annotations import override, DeveloperAPI from ray.rllib.utils.typing import EnvConfigDict, EnvType, \ PartialTrainerConfigDict, ResultDict, TrainerConfigDict logger = logging.getLogger(__name__) # TODO: Deprecate Trainer template generated by this utility function. # Instead, users should sub-class Trainer directly and override some of its # methods, e.g. `Trainer.setup()`. @DeveloperAPI def build_trainer( name: str, *, default_config: Optional[TrainerConfigDict] = None, validate_config: Optional[Callable[[TrainerConfigDict], None]] = None, default_policy: Optional[Type[Policy]] = None, get_policy_class: Optional[Callable[[TrainerConfigDict], Optional[Type[ Policy]]]] = None, validate_env: Optional[Callable[[EnvType, EnvContext], None]] = None, before_init: Optional[Callable[[Trainer], None]] = None, after_init: Optional[Callable[[Trainer], None]] = None, before_evaluate_fn: Optional[Callable[[Trainer], None]] = None, mixins: Optional[List[type]] = None, execution_plan: Optional[Union[Callable[ [WorkerSet, TrainerConfigDict], Iterable[ResultDict]], Callable[[ Trainer, WorkerSet, TrainerConfigDict ], Iterable[ResultDict]]]] = None, allow_unknown_configs: bool = False, allow_unknown_subkeys: Optional[List[str]] = None, override_all_subkeys_if_type_changes: Optional[List[str]] = None, ) -> Type[Trainer]: """Helper function for defining a custom Trainer class. Functions will be run in this order to initialize the trainer: 1. Config setup: validate_config, get_policy. 2. Worker setup: before_init, execution_plan. 3. Post setup: after_init. Args: name: name of the trainer (e.g., "PPO") default_config: The default config dict of the algorithm, otherwise uses the Trainer default config. validate_config: Optional callable that takes the config to check for correctness. It may mutate the config as needed. default_policy: The default Policy class to use if `get_policy_class` returns None. get_policy_class: Optional callable that takes a config and returns the policy class or None. If None is returned, will use `default_policy` (which must be provided then). validate_env: Optional callable to validate the generated environment (only on worker=0). before_init: Optional callable to run before anything is constructed inside Trainer (Workers with Policies, execution plan, etc..). Takes the Trainer instance as argument. after_init: Optional callable to run at the end of trainer init (after all Workers and the exec. plan have been constructed). Takes the Trainer instance as argument. before_evaluate_fn: Callback to run before evaluation. This takes the trainer instance as argument. mixins: List of any class mixins for the returned trainer class. These mixins will be applied in order and will have higher precedence than the Trainer class. execution_plan: Optional callable that sets up the distributed execution workflow. allow_unknown_configs: Whether to allow unknown top-level config keys. allow_unknown_subkeys: List of top-level keys with value=dict, for which new sub-keys are allowed to be added to the value dict. Appends to Trainer class defaults. override_all_subkeys_if_type_changes: List of top level keys with value=dict, for which we always override the entire value (dict), iff the "type" key in that value dict changes. Appends to Trainer class defaults. Returns: A Trainer sub-class configured by the specified args. """ original_kwargs = locals().copy() base = add_mixins(Trainer, mixins) class trainer_cls(base): _name = name _default_config = default_config or COMMON_CONFIG _policy_class = default_policy def __init__(self, config=None, env=None, logger_creator=None): Trainer.__init__(self, config, env, logger_creator) @override(base) def setup(self, config: PartialTrainerConfigDict): if allow_unknown_subkeys is not None: self._allow_unknown_subkeys += allow_unknown_subkeys self._allow_unknown_configs = allow_unknown_configs if override_all_subkeys_if_type_changes is not None: self._override_all_subkeys_if_type_changes += \ override_all_subkeys_if_type_changes super().setup(config) def _init(self, config: TrainerConfigDict, env_creator: Callable[[EnvConfigDict], EnvType]): # No `get_policy_class` function. if get_policy_class is None: # Default_policy must be provided (unless in multi-agent mode, # where each policy can have its own default policy class). if not config["multiagent"]["policies"]: assert default_policy is not None # Query the function for a class to use. else: self._policy_class = get_policy_class(config) # If None returned, use default policy (must be provided). if self._policy_class is None: assert default_policy is not None self._policy_class = default_policy if before_init: before_init(self) # Creating all workers (excluding evaluation workers). self.workers = self._make_workers( env_creator=env_creator, validate_env=validate_env, policy_class=self._policy_class, config=config, num_workers=self.config["num_workers"]) # If execution plan is not provided (None), the Trainer will use # it's already existing default `execution_plan()` static method # instead. if execution_plan is not None: self.execution_plan = execution_plan self.train_exec_impl = self.execution_plan( self.workers, config, **self._kwargs_for_execution_plan()) if after_init: after_init(self) @staticmethod @override(Trainer) def _validate_config(config: PartialTrainerConfigDict, trainer_obj_or_none: Optional["Trainer"] = None): # Call super (Trainer) validation method first. Trainer._validate_config(config, trainer_obj_or_none) # Then call user defined one, if any. if validate_config is not None: validate_config(config) @override(Trainer) def _before_evaluate(self): if before_evaluate_fn: before_evaluate_fn(self) @staticmethod @override(Trainer) def with_updates(**overrides) -> Type[Trainer]: """Build a copy of this trainer class with the specified overrides. Keyword Args: overrides (dict): use this to override any of the arguments originally passed to build_trainer() for this policy. Returns: Type[Trainer]: A the Trainer sub-class using `original_kwargs` and `overrides`. Examples: >>> MyClass = SomeOtherClass.with_updates({"name": "Mine"}) >>> issubclass(MyClass, SomeOtherClass) ... False >>> issubclass(MyClass, Trainer) ... True """ return build_trainer(**dict(original_kwargs, **overrides)) def __repr__(self): return self._name trainer_cls.__name__ = name trainer_cls.__qualname__ = name return trainer_cls