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[Enhancement] Improve Typing Support / Ensure every function has return type

See original GitHub issue

One of the goals for v1 release was to improve typing support. This issue is only concerned return types. I wanted to improve the type support so I wrote a script to parse python code and filter out function definitions and class method definitions to find out what needs typing. In the process, I figured that this would be quite useful to add as a test.

Suggestion

Add a test to ensure that every function has a return type.

This isn’t to be confused with type verification, e.g. bad return types.

Special Cases

In some cases we may want to avoid adding a return type, a decorator could be added onto the function to make it ignored by the test.

An exhaustive list of functions that are missing return types:

Missing types:
stable_baselines3/common/vec_env/dummy_vec_env.py::DummyVecEnv::step_async
stable_baselines3/common/vec_env/dummy_vec_env.py::DummyVecEnv::step_wait
stable_baselines3/common/vec_env/dummy_vec_env.py::DummyVecEnv::seed
stable_baselines3/common/vec_env/dummy_vec_env.py::DummyVecEnv::reset
stable_baselines3/common/vec_env/dummy_vec_env.py::DummyVecEnv::close
stable_baselines3/common/vec_env/dummy_vec_env.py::DummyVecEnv::render
stable_baselines3/common/vec_env/dummy_vec_env.py::DummyVecEnv::_save_obs
stable_baselines3/common/vec_env/dummy_vec_env.py::DummyVecEnv::_obs_from_buf
stable_baselines3/common/vec_env/dummy_vec_env.py::DummyVecEnv::get_attr
stable_baselines3/common/vec_env/dummy_vec_env.py::DummyVecEnv::set_attr
stable_baselines3/common/vec_env/dummy_vec_env.py::DummyVecEnv::env_method
stable_baselines3/common/vec_env/dummy_vec_env.py::DummyVecEnv::_get_target_envs
stable_baselines3/common/logger.py::SeqWriter::write_sequence
stable_baselines3/common/vec_env/vec_normalize.py::VecNormalize::__getstate__
stable_baselines3/common/vec_env/vec_normalize.py::VecNormalize::__setstate__
stable_baselines3/common/vec_env/vec_normalize.py::VecNormalize::set_venv
stable_baselines3/common/vec_env/vec_normalize.py::VecNormalize::step_wait
stable_baselines3/common/vec_env/vec_normalize.py::VecNormalize::_update_reward
stable_baselines3/common/vec_env/vec_normalize.py::VecNormalize::normalize_obs
stable_baselines3/common/vec_env/vec_normalize.py::VecNormalize::normalize_reward
stable_baselines3/common/vec_env/vec_normalize.py::VecNormalize::unnormalize_obs
stable_baselines3/common/vec_env/vec_normalize.py::VecNormalize::unnormalize_reward
stable_baselines3/common/vec_env/vec_normalize.py::VecNormalize::get_original_obs
stable_baselines3/common/vec_env/vec_normalize.py::VecNormalize::get_original_reward
stable_baselines3/common/vec_env/vec_normalize.py::VecNormalize::reset
stable_baselines3/common/utils.py::check_for_correct_spaces
stable_baselines3/td3/policies.py::TD3Policy::forward
stable_baselines3/common/cmd_util.py::make_vec_env
stable_baselines3/common/cmd_util.py::make_atari_env
stable_baselines3/common/buffers.py::BaseBuffer::sample
stable_baselines3/common/buffers.py::BaseBuffer::_get_samples
stable_baselines3/common/vec_env/vec_frame_stack.py::VecFrameStack::step_wait
stable_baselines3/common/vec_env/vec_frame_stack.py::VecFrameStack::reset
stable_baselines3/common/vec_env/vec_frame_stack.py::VecFrameStack::close
stable_baselines3/common/monitor.py::Monitor::close
stable_baselines3/common/atari_wrappers.py::MaxAndSkipEnv::reset
stable_baselines3/common/evaluation.py::evaluate_policy
stable_baselines3/common/policies.py::BasePolicy::forward
stable_baselines3/common/policies.py::BasePolicy::load_from_vector
stable_baselines3/common/vec_env/vec_video_recorder.py::VecVideoRecorder::reset
stable_baselines3/common/vec_env/vec_video_recorder.py::VecVideoRecorder::start_video_recorder
stable_baselines3/common/vec_env/vec_video_recorder.py::VecVideoRecorder::_video_enabled
stable_baselines3/common/vec_env/vec_video_recorder.py::VecVideoRecorder::step_wait
stable_baselines3/common/vec_env/vec_video_recorder.py::VecVideoRecorder::close_video_recorder
stable_baselines3/common/vec_env/vec_video_recorder.py::VecVideoRecorder::close
stable_baselines3/common/callbacks.py::EvalCallback::_init_callback
stable_baselines3/common/off_policy_algorithm.py::OffPolicyAlgorithm::_setup_model
stable_baselines3/common/off_policy_algorithm.py::OffPolicyAlgorithm::save_replay_buffer
stable_baselines3/common/off_policy_algorithm.py::OffPolicyAlgorithm::load_replay_buffer
stable_baselines3/common/vec_env/util.py::copy_obs_dict
stable_baselines3/common/vec_env/util.py::dict_to_obs
stable_baselines3/common/vec_env/util.py::obs_space_info
stable_baselines3/common/vec_env/vec_check_nan.py::VecCheckNan::step_async
stable_baselines3/common/vec_env/vec_check_nan.py::VecCheckNan::step_wait
stable_baselines3/common/vec_env/vec_check_nan.py::VecCheckNan::reset
stable_baselines3/common/vec_env/vec_check_nan.py::VecCheckNan::_check_val
stable_baselines3/common/vec_env/subproc_vec_env.py::_worker
stable_baselines3/common/vec_env/subproc_vec_env.py::SubprocVecEnv::step_async
stable_baselines3/common/vec_env/subproc_vec_env.py::SubprocVecEnv::step_wait
stable_baselines3/common/vec_env/subproc_vec_env.py::SubprocVecEnv::seed
stable_baselines3/common/vec_env/subproc_vec_env.py::SubprocVecEnv::reset
stable_baselines3/common/vec_env/subproc_vec_env.py::SubprocVecEnv::close
stable_baselines3/common/vec_env/subproc_vec_env.py::SubprocVecEnv::get_attr
stable_baselines3/common/vec_env/subproc_vec_env.py::SubprocVecEnv::set_attr
stable_baselines3/common/vec_env/subproc_vec_env.py::SubprocVecEnv::env_method
stable_baselines3/common/vec_env/subproc_vec_env.py::SubprocVecEnv::_get_target_remotes
stable_baselines3/common/vec_env/subproc_vec_env.py::_flatten_obs
stable_baselines3/common/noise.py::VectorizedActionNoise::base_noise
stable_baselines3/common/vec_env/base_vec_env.py::VecEnv::reset
stable_baselines3/common/vec_env/base_vec_env.py::VecEnv::step_async
stable_baselines3/common/vec_env/base_vec_env.py::VecEnv::step_wait
stable_baselines3/common/vec_env/base_vec_env.py::VecEnv::close
stable_baselines3/common/vec_env/base_vec_env.py::VecEnv::get_attr
stable_baselines3/common/vec_env/base_vec_env.py::VecEnv::set_attr
stable_baselines3/common/vec_env/base_vec_env.py::VecEnv::env_method
stable_baselines3/common/vec_env/base_vec_env.py::VecEnv::step
stable_baselines3/common/vec_env/base_vec_env.py::VecEnv::render
stable_baselines3/common/vec_env/base_vec_env.py::VecEnv::unwrapped
stable_baselines3/common/vec_env/base_vec_env.py::VecEnv::getattr_depth_check
stable_baselines3/common/vec_env/base_vec_env.py::VecEnv::_get_indices
stable_baselines3/common/vec_env/base_vec_env.py::VecEnvWrapper::step_async
stable_baselines3/common/vec_env/base_vec_env.py::VecEnvWrapper::reset
stable_baselines3/common/vec_env/base_vec_env.py::VecEnvWrapper::step_wait
stable_baselines3/common/vec_env/base_vec_env.py::VecEnvWrapper::seed
stable_baselines3/common/vec_env/base_vec_env.py::VecEnvWrapper::close
stable_baselines3/common/vec_env/base_vec_env.py::VecEnvWrapper::render
stable_baselines3/common/vec_env/base_vec_env.py::VecEnvWrapper::get_images
stable_baselines3/common/vec_env/base_vec_env.py::VecEnvWrapper::get_attr
stable_baselines3/common/vec_env/base_vec_env.py::VecEnvWrapper::set_attr
stable_baselines3/common/vec_env/base_vec_env.py::VecEnvWrapper::env_method
stable_baselines3/common/vec_env/base_vec_env.py::VecEnvWrapper::__getattr__
stable_baselines3/common/vec_env/base_vec_env.py::VecEnvWrapper::_get_all_attributes
stable_baselines3/common/vec_env/base_vec_env.py::VecEnvWrapper::getattr_recursive
stable_baselines3/common/vec_env/base_vec_env.py::VecEnvWrapper::getattr_depth_check
stable_baselines3/common/vec_env/base_vec_env.py::CloudpickleWrapper::__getstate__
stable_baselines3/common/vec_env/base_vec_env.py::CloudpickleWrapper::__setstate__
stable_baselines3/dqn/dqn.py::DQN::_on_step
stable_baselines3/common/base_class.py::BaseAlgorithm::load

Issue Analytics

State:
Created 3 years ago
Comments:5 (4 by maintainers)

Top GitHub Comments

1reaction

PartiallyTypedcommented, Jul 2, 2020

It is nice to check to improve typing (mostly the vec env missing)

I am not familiar with the vec env code base, but I can deal with the others and open a PR.

It is nice to check to improve typing (mostly the vec env missing) but I would not enforce it, in some cases (abstract classes), it is easier not to specify return type

I am leaving this here as a future reference.

import ast
import pathlib


def missing_return_types():
    root = pathlib.Path("./stable_baselines3")
    files = set(root.iterdir())
    pyfiles = set()
    while files:
        f = files.pop()
        if f.is_dir():
            files.update(set(f.iterdir()))
        elif f.suffix==".py":
            pyfiles.add(f)
    invalid_definitions = []
    def recursive_iter(node, path):
        if isinstance(node, ast.FunctionDef) and node.returns is None:
            if node.name not in ("__init__", "__del__"):
                invalid_definitions.append((*path, node.name))
        if isinstance(node, ast.ClassDef):
            for newnode in ast.iter_child_nodes(node):
                recursive_iter(newnode, (*path, node.name))
        if isinstance(node, ast.Module):
            for newnode in ast.iter_child_nodes(node):
                recursive_iter(newnode, path)
    for file in pyfiles:
        recursive_iter(ast.parse(file.read_text(), filename=str(file)), (str(file),))
    invalid_definitions = list(map("::".join, invalid_definitions))
    print("Missing types:", *invalid_definitions, sep="\n")

0reactions

PartiallyTypedcommented, Jul 6, 2020

@araffin

I was playing with ‘typing.Generic’ and it is possible to define a subclass that returns a specific type without complains that the return type is different.

i.e the base policy hints TypeVar and the subclass hints the correct type. Static typers are aware of the subclass so when a policy returns an action and log prob, static typers know it returns two items.