def trajectory(obs_space: gym.Space, act_space: gym.Space,
length: int) -> types.Trajectory:
"""Fixture to generate trajectory of length `length` iid sampled from spaces."""
obs = np.array([obs_space.sample() for _ in range(length + 1)])
acts = np.array([act_space.sample() for _ in range(length)])
infos = np.array([{} for _ in range(length)])
return types.Trajectory(obs=obs, acts=acts, infos=infos)
def _slice_trajectory(trajectory: types.Trajectory, start: int,
end: int) -> types.Trajectory:
"""Slice trajectory from timestep start to timestep end."""
infos = trajectory.infos[
start:end] if trajectory.infos is not None else None
return types.Trajectory(
obs=trajectory.obs[start:end + 1],
acts=trajectory.acts[start:end],
infos=infos,
)
def test_zero_length_fails():
"""Check zero-length trajectory and transitions fail."""
empty = np.array([])
with pytest.raises(ValueError, match=r"Degenerate trajectory.*"):
types.Trajectory(obs=np.array([42]), acts=empty, infos=None)
with pytest.raises(ValueError, match=r"Must have non-zero number of.*"):
types.Transitions(
obs=empty,
acts=empty,
next_obs=empty,
dones=empty.astype(np.bool),
)
def test_zero_length_fails():
"""Check zero-length trajectory and transitions fail."""
empty = np.array([])
with pytest.raises(ValueError, match=r"Degenerate trajectory.*"):
types.Trajectory(obs=np.array([42]), acts=empty, infos=None)