EnvLogger is a standard dm_env.Environment class wrapper that records interactions between a real environment and an agent. These interactions are saved on disk as trajectories and can be retrieved in whole, by individual timesteps or by specific episodes.

To better categorize your logged data, you may want to add some tags in the metadata when you construct the logger wrapper. The metadata is written once per EnvLogger instance.

env = envlogger.EnvLogger(
    env,
    data_directory='/tmp/experiment_logs',
    metadata={
        'environment_type': 'dm_control',
        'agent_type': 'D4PG'
    })

Most of the time, it is just a one-liner wrapper, e.g.

import envlogger
from envlogger.testing import catch_env
import numpy as np

env = catch_env.Catch()
with envlogger.EnvLogger(
    env, data_directory='/tmp/experiment_logs') as env:

  env.reset()
  for step in range(100):
    action = np.random.randint(low=0, high=3)
    timestep = env.step(action)

Reader can read stored trajectories. Example:

from envlogger import reader

with reader.Reader(
    data_directory='/tmp/experiment_logs') as r:
  for episode in r.episodes:
    for step in episode:
       # step is a step_data.StepData.
       # Use step.timestep.observation, step.timestep.reward, step.action etc...

EnvLogger currently only supports Linux based OSes and Python 3.

You can install EnvLogger via pip:

pip install envlogger

For this option you will need to install Bazel and GMP (libgmp-dev on Debian-based systems). Please note that Bazel versions >4.0 are not supported. Our recommended version is 3.7.2. Then:

git clone https://github.com/deepmind/envlogger/
cd envlogger
bazel test --test_output=errors envlogger/...

We provide a Docker image that can be used to run tests in a more controlled environment. You can run it as follows:

sh docker/build.sh
docker run -it envlogger bash
bazel test --test_output=errors envlogger/...

Wrapping your environment with EnvLogger adds an approximately 2 millisecond overhead per environment step. See the following difference in distributions in the case of random agent on a 100 steps per second Catch environment (measured in milliseconds).

We greatly appreciate all the support from the TF-Agents team in setting up building and testing for EnvLogger.