flatland.core.env_observation_builder module

ObservationBuilder objects are objects that can be passed to environments designed for customizability. The ObservationBuilder-derived custom classes implement 2 functions, reset() and get() or get(handle).

• reset() is called after each environment reset, to allow for pre-computing relevant data.

• get() is called whenever an observation has to be computed, potentially for each agent independently in case of multi-agent environments.

class flatland.core.env_observation_builder.DummyObservationBuilder

Bases: ObservationBuilder[bool]

DummyObservationBuilder class which returns dummy observations This is used in the evaluation service

get(handle: int = 0) → bool

Called whenever an observation has to be computed for the env environment, possibly for each agent independently (agent id handle).

Parameters

handleint, optional

Handle of the agent for which to compute the observation vector.

Returns

function

An observation structure, specific to the corresponding environment.

reset()

Called after each environment reset.

class flatland.core.env_observation_builder.ObservationBuilder

Bases: Generic[ObservationType]

ObservationBuilder base class.

get(handle: int = 0) → ObservationType

Called whenever an observation has to be computed for the env environment, possibly for each agent independently (agent id handle).

Parameters

handleint, optional

Handle of the agent for which to compute the observation vector.

Returns

function

An observation structure, specific to the corresponding environment.

get_many(handles: List[int] | None = None) → Dict[int, ObservationType]

Called whenever an observation has to be computed for the env environment, for each agent with handle in the handles list.

Parameters

handleslist of handles, optional

List with the handles of the agents for which to compute the observation vector.

Returns

function

A dictionary of observation structures, specific to the corresponding environment, with handles from handles as keys.

reset()

Called after each environment reset.

set_env(env: Environment)