Files
Gymnasium/api/wrappers/index.html
2025-02-26 11:56:33 +00:00

939 lines
74 KiB
HTML
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!doctype html>
<html class="no-js" lang="en" data-content_root="../../">
<head><meta charset="utf-8"/>
<meta name="viewport" content="width=device-width,initial-scale=1"/>
<meta name="color-scheme" content="light dark">
<meta name="description" content="A standard API for reinforcement learning and a diverse set of reference environments (formerly Gym)">
<meta property="og:title" content="Gymnasium Documentation" />
<meta property="og:type" content="website" />
<meta property="og:description" content="A standard API for reinforcement learning and a diverse set of reference environments (formerly Gym)" />
<meta property="og:url" content="https://gymnasium.farama.org/api/wrappers.html" /><meta property="og:image" content="https://gymnasium.farama.org/_static/img/gymnasium-github.png" /><meta name="twitter:card" content="summary_large_image"><meta name="viewport" content="width=device-width, initial-scale=1" />
<link rel="index" title="Index" href="../../genindex/" /><link rel="search" title="Search" href="../../search/" /><link rel="next" title="List of Wrappers" href="table/" /><link rel="prev" title="Spaces Utils" href="../spaces/utils/" />
<link rel="canonical" href="https://gymnasium.farama.org/api/wrappers.html" />
<link rel="shortcut icon" href="../../_static/favicon.png"/><!-- Generated with Sphinx 7.4.7 and Furo 2023.08.19.dev1 -->
<title>Wrappers - Gymnasium Documentation</title>
<link rel="stylesheet" type="text/css" href="../../_static/pygments.css?v=8f2a1f02" />
<link rel="stylesheet" type="text/css" href="../../_static/styles/furo.css?v=3e7f4c72" />
<link rel="stylesheet" type="text/css" href="../../_static/sg_gallery.css?v=61a4c737" />
<link rel="stylesheet" type="text/css" href="../../_static/sg_gallery-binder.css?v=f4aeca0c" />
<link rel="stylesheet" type="text/css" href="../../_static/sg_gallery-dataframe.css?v=2082cf3c" />
<link rel="stylesheet" type="text/css" href="../../_static/sg_gallery-rendered-html.css?v=1277b6f3" />
<link rel="stylesheet" type="text/css" href="../../_static/styles/furo-extensions.css?v=82c8b628" />
<style>
body {
--color-code-background: #f8f8f8;
--color-code-foreground: black;
}
@media not print {
body[data-theme="dark"] {
--color-code-background: #202020;
--color-code-foreground: #d0d0d0;
}
@media (prefers-color-scheme: dark) {
body:not([data-theme="light"]) {
--color-code-background: #202020;
--color-code-foreground: #d0d0d0;
}
}
}
</style></head>
<body>
<header class="farama-header" aria-label="Farama header">
<div class="farama-header__container">
<div class="farama-header__left--mobile">
<label class="nav-overlay-icon" for="__navigation">
<div class="visually-hidden">Toggle site navigation sidebar</div>
<svg viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg">
<defs></defs>
<line x1="0.5" y1="4" x2="23.5" y2="4"></line>
<line x1="0.232" y1="12" x2="23.5" y2="12"></line>
<line x1="0.232" y1="20" x2="23.5" y2="20"></line>
</svg>
</label>
</div>
<div class="farama-header__left farama-header__center--mobile">
<a href="../../">
<img class="farama-header__logo only-light" src="../../_static/img/gymnasium_black.svg" alt="Light Logo"/>
<img class="farama-header__logo only-dark" src="../../_static/img/gymnasium_white.svg" alt="Dark Logo"/>
<span class="farama-header__title">Gymnasium Documentation</span>
</a>
</div>
<div class="farama-header__right">
<div class="farama-header-menu">
<button class="farama-header-menu__btn" aria-label="Open Farama Menu" aria-expanded="false" aria-haspopup="true" aria-controls="farama-menu">
<img class="farama-black-logo-invert" src="../../_static/img/farama-logo-header.svg">
<svg viewBox="0 0 24 24" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg">
<polyline style="stroke-linecap: round; stroke-linejoin: round; fill: none; stroke-width: 2px;" points="1 7 12 18 23 7"></polyline>
</svg>
</button>
<div class="farama-header-menu-container farama-hidden" aria-hidden="true" id="farama-menu">
<div class="farama-header-menu__header">
<a href="https://farama.org">
<img class="farama-header-menu__logo farama-white-logo-invert" src="../../_static/img/farama_solid_white.svg" alt="Farama Foundation logo">
<span>Farama Foundation</span>
</a>
<div class="farama-header-menu-header__right">
<button id="farama-close-menu">
<svg viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg" fill="none" stroke="currentColor"
stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="icon-close">
<line x1="3" y1="21" x2="21" y2="3"></line>
<line x1="3" y1="3" x2="21" y2="21"></line>
</svg>
</button>
</div>
</div>
<div class="farama-header-menu__body">
<!-- Response from farama.org/api/projects.json -->
</div>
</div>
</div>
</div>
</div>
</header>
<script>
document.body.dataset.theme = localStorage.getItem("theme") || "auto";
</script>
<svg xmlns="http://www.w3.org/2000/svg" style="display: none;">
<symbol id="svg-toc" viewBox="0 0 24 24">
<title>Contents</title>
<svg stroke="currentColor" fill="currentColor" stroke-width="0" viewBox="0 0 1024 1024">
<path d="M408 442h480c4.4 0 8-3.6 8-8v-56c0-4.4-3.6-8-8-8H408c-4.4 0-8 3.6-8 8v56c0 4.4 3.6 8 8 8zm-8 204c0 4.4 3.6 8 8 8h480c4.4 0 8-3.6 8-8v-56c0-4.4-3.6-8-8-8H408c-4.4 0-8 3.6-8 8v56zm504-486H120c-4.4 0-8 3.6-8 8v56c0 4.4 3.6 8 8 8h784c4.4 0 8-3.6 8-8v-56c0-4.4-3.6-8-8-8zm0 632H120c-4.4 0-8 3.6-8 8v56c0 4.4 3.6 8 8 8h784c4.4 0 8-3.6 8-8v-56c0-4.4-3.6-8-8-8zM115.4 518.9L271.7 642c5.8 4.6 14.4.5 14.4-6.9V388.9c0-7.4-8.5-11.5-14.4-6.9L115.4 505.1a8.74 8.74 0 0 0 0 13.8z"/>
</svg>
</symbol>
<symbol id="svg-menu" viewBox="0 0 24 24">
<title>Menu</title>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="currentColor"
stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather-menu">
<line x1="3" y1="12" x2="21" y2="12"></line>
<line x1="3" y1="6" x2="21" y2="6"></line>
<line x1="3" y1="18" x2="21" y2="18"></line>
</svg>
</symbol>
<symbol id="svg-arrow-right" viewBox="0 0 24 24">
<title>Expand</title>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="currentColor"
stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather-chevron-right">
<polyline points="9 18 15 12 9 6"></polyline>
</svg>
</symbol>
<symbol id="svg-sun" viewBox="0 0 24 24">
<title>Light mode</title>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="currentColor"
stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round" class="feather-sun">
<circle cx="12" cy="12" r="5"></circle>
<line x1="12" y1="1" x2="12" y2="3"></line>
<line x1="12" y1="21" x2="12" y2="23"></line>
<line x1="4.22" y1="4.22" x2="5.64" y2="5.64"></line>
<line x1="18.36" y1="18.36" x2="19.78" y2="19.78"></line>
<line x1="1" y1="12" x2="3" y2="12"></line>
<line x1="21" y1="12" x2="23" y2="12"></line>
<line x1="4.22" y1="19.78" x2="5.64" y2="18.36"></line>
<line x1="18.36" y1="5.64" x2="19.78" y2="4.22"></line>
</svg>
</symbol>
<symbol id="svg-moon" viewBox="0 0 24 24">
<title>Dark mode</title>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="currentColor"
stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round" class="icon-tabler-moon">
<path stroke="none" d="M0 0h24v24H0z" fill="none" />
<path d="M12 3c.132 0 .263 0 .393 0a7.5 7.5 0 0 0 7.92 12.446a9 9 0 1 1 -8.313 -12.454z" />
</svg>
</symbol>
<symbol id="svg-sun-half" viewBox="0 0 24 24">
<title>Auto light/dark mode</title>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" fill="none" stroke="currentColor"
stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round" class="icon-tabler-shadow">
<path stroke="none" d="M0 0h24v24H0z" fill="none"/>
<circle cx="12" cy="12" r="9" />
<path d="M13 12h5" />
<path d="M13 15h4" />
<path d="M13 18h1" />
<path d="M13 9h4" />
<path d="M13 6h1" />
</svg>
</symbol>
</svg>
<input type="checkbox" class="sidebar-toggle" name="__navigation" id="__navigation">
<input type="checkbox" class="sidebar-toggle" name="__toc" id="__toc">
<label class="overlay sidebar-overlay" for="__navigation">
<div class="visually-hidden">Hide navigation sidebar</div>
</label>
<label class="overlay toc-overlay" for="__toc">
<div class="visually-hidden">Hide table of contents sidebar</div>
</label>
<div class="page">
<!--<header class="mobile-header">
<div class="header-left">
<label class="nav-overlay-icon" for="__navigation">
<div class="visually-hidden">Toggle site navigation sidebar</div>
<i class="icon"><svg><use href="#svg-menu"></use></svg></i>
</label>
</div>
<div class="header-center">
<a href="../../"><div class="brand">Gymnasium Documentation</div></a>
</div>
<div class="header-right">
<div class="theme-toggle-container theme-toggle-header">
<button class="theme-toggle">
<div class="visually-hidden">Toggle Light / Dark / Auto color theme</div>
<svg class="theme-icon-when-auto"><use href="#svg-sun-half"></use></svg>
<svg class="theme-icon-when-dark"><use href="#svg-moon"></use></svg>
<svg class="theme-icon-when-light"><use href="#svg-sun"></use></svg>
</button>
</div>
<label class="toc-overlay-icon toc-header-icon" for="__toc">
<div class="visually-hidden">Toggle table of contents sidebar</div>
<i class="icon"><svg><use href="#svg-toc"></use></svg></i>
</label>
</div>
</header>-->
<aside class="sidebar-drawer">
<div class="sidebar-container">
<div class="sidebar-sticky"><a class="farama-sidebar__title" href="../../">
<img class="farama-header__logo only-light" src="../../_static/img/gymnasium_black.svg" alt="Light Logo"/>
<img class="farama-header__logo only-dark" src="../../_static/img/gymnasium_white.svg" alt="Dark Logo"/>
<span class="farama-header__title">Gymnasium Documentation</span>
</a><form class="sidebar-search-container" method="get" action="../../search/" role="search">
<input class="sidebar-search" placeholder="Search" name="q" aria-label="Search">
<input type="hidden" name="check_keywords" value="yes">
<input type="hidden" name="area" value="default">
</form>
<div id="searchbox"></div><div class="sidebar-scroll"><div class="sidebar-tree">
<p class="caption" role="heading"><span class="caption-text">Introduction</span></p>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../../introduction/basic_usage/">Basic Usage</a></li>
<li class="toctree-l1"><a class="reference internal" href="../../introduction/train_agent/">Training an Agent</a></li>
<li class="toctree-l1"><a class="reference internal" href="../../introduction/create_custom_env/">Create a Custom Environment</a></li>
<li class="toctree-l1"><a class="reference internal" href="../../introduction/record_agent/">Recording Agents</a></li>
<li class="toctree-l1"><a class="reference internal" href="../../introduction/speed_up_env/">Speeding Up Training</a></li>
<li class="toctree-l1"><a class="reference internal" href="../../introduction/gym_compatibility/">Compatibility with Gym</a></li>
<li class="toctree-l1"><a class="reference internal" href="../../introduction/migration_guide/">Migration Guide - v0.21 to v1.0.0</a></li>
</ul>
<p class="caption" role="heading"><span class="caption-text">API</span></p>
<ul class="current">
<li class="toctree-l1"><a class="reference internal" href="../env/">Env</a></li>
<li class="toctree-l1"><a class="reference internal" href="../registry/">Make and register</a></li>
<li class="toctree-l1 has-children"><a class="reference internal" href="../spaces/">Spaces</a><input class="toctree-checkbox" id="toctree-checkbox-1" name="toctree-checkbox-1" role="switch" type="checkbox"/><label for="toctree-checkbox-1"><div class="visually-hidden">Toggle navigation of Spaces</div><i class="icon"><svg><use href="#svg-arrow-right"></use></svg></i></label><ul>
<li class="toctree-l2"><a class="reference internal" href="../spaces/fundamental/">Fundamental Spaces</a></li>
<li class="toctree-l2"><a class="reference internal" href="../spaces/composite/">Composite Spaces</a></li>
<li class="toctree-l2"><a class="reference internal" href="../spaces/utils/">Spaces Utils</a></li>
</ul>
</li>
<li class="toctree-l1 current has-children current-page"><a class="current reference internal" href="#">Wrappers</a><input checked="" class="toctree-checkbox" id="toctree-checkbox-2" name="toctree-checkbox-2" role="switch" type="checkbox"/><label for="toctree-checkbox-2"><div class="visually-hidden">Toggle navigation of Wrappers</div><i class="icon"><svg><use href="#svg-arrow-right"></use></svg></i></label><ul>
<li class="toctree-l2"><a class="reference internal" href="table/">List of Wrappers</a></li>
<li class="toctree-l2"><a class="reference internal" href="misc_wrappers/">Misc Wrappers</a></li>
<li class="toctree-l2"><a class="reference internal" href="action_wrappers/">Action Wrappers</a></li>
<li class="toctree-l2"><a class="reference internal" href="observation_wrappers/">Observation Wrappers</a></li>
<li class="toctree-l2"><a class="reference internal" href="reward_wrappers/">Reward Wrappers</a></li>
</ul>
</li>
<li class="toctree-l1 has-children"><a class="reference internal" href="../vector/">Vectorize</a><input class="toctree-checkbox" id="toctree-checkbox-3" name="toctree-checkbox-3" role="switch" type="checkbox"/><label for="toctree-checkbox-3"><div class="visually-hidden">Toggle navigation of Vectorize</div><i class="icon"><svg><use href="#svg-arrow-right"></use></svg></i></label><ul>
<li class="toctree-l2"><a class="reference internal" href="../vector/wrappers/">Wrappers</a></li>
<li class="toctree-l2"><a class="reference internal" href="../vector/async_vector_env/">AsyncVectorEnv</a></li>
<li class="toctree-l2"><a class="reference internal" href="../vector/sync_vector_env/">SyncVectorEnv</a></li>
<li class="toctree-l2"><a class="reference internal" href="../vector/utils/">Utility functions</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="../utils/">Utility functions</a></li>
<li class="toctree-l1"><a class="reference internal" href="../functional/">Functional Env</a></li>
</ul>
<p class="caption" role="heading"><span class="caption-text">Environments</span></p>
<ul>
<li class="toctree-l1 has-children"><a class="reference internal" href="../../environments/classic_control/">Classic Control</a><input class="toctree-checkbox" id="toctree-checkbox-4" name="toctree-checkbox-4" role="switch" type="checkbox"/><label for="toctree-checkbox-4"><div class="visually-hidden">Toggle navigation of Classic Control</div><i class="icon"><svg><use href="#svg-arrow-right"></use></svg></i></label><ul>
<li class="toctree-l2"><a class="reference internal" href="../../environments/classic_control/acrobot/">Acrobot</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../environments/classic_control/cart_pole/">Cart Pole</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../environments/classic_control/mountain_car_continuous/">Mountain Car Continuous</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../environments/classic_control/mountain_car/">Mountain Car</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../environments/classic_control/pendulum/">Pendulum</a></li>
</ul>
</li>
<li class="toctree-l1 has-children"><a class="reference internal" href="../../environments/box2d/">Box2D</a><input class="toctree-checkbox" id="toctree-checkbox-5" name="toctree-checkbox-5" role="switch" type="checkbox"/><label for="toctree-checkbox-5"><div class="visually-hidden">Toggle navigation of Box2D</div><i class="icon"><svg><use href="#svg-arrow-right"></use></svg></i></label><ul>
<li class="toctree-l2"><a class="reference internal" href="../../environments/box2d/bipedal_walker/">Bipedal Walker</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../environments/box2d/car_racing/">Car Racing</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../environments/box2d/lunar_lander/">Lunar Lander</a></li>
</ul>
</li>
<li class="toctree-l1 has-children"><a class="reference internal" href="../../environments/toy_text/">Toy Text</a><input class="toctree-checkbox" id="toctree-checkbox-6" name="toctree-checkbox-6" role="switch" type="checkbox"/><label for="toctree-checkbox-6"><div class="visually-hidden">Toggle navigation of Toy Text</div><i class="icon"><svg><use href="#svg-arrow-right"></use></svg></i></label><ul>
<li class="toctree-l2"><a class="reference internal" href="../../environments/toy_text/blackjack/">Blackjack</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../environments/toy_text/taxi/">Taxi</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../environments/toy_text/cliff_walking/">Cliff Walking</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../environments/toy_text/frozen_lake/">Frozen Lake</a></li>
</ul>
</li>
<li class="toctree-l1 has-children"><a class="reference internal" href="../../environments/mujoco/">MuJoCo</a><input class="toctree-checkbox" id="toctree-checkbox-7" name="toctree-checkbox-7" role="switch" type="checkbox"/><label for="toctree-checkbox-7"><div class="visually-hidden">Toggle navigation of MuJoCo</div><i class="icon"><svg><use href="#svg-arrow-right"></use></svg></i></label><ul>
<li class="toctree-l2"><a class="reference internal" href="../../environments/mujoco/ant/">Ant</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../environments/mujoco/half_cheetah/">Half Cheetah</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../environments/mujoco/hopper/">Hopper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../environments/mujoco/humanoid/">Humanoid</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../environments/mujoco/humanoid_standup/">Humanoid Standup</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../environments/mujoco/inverted_double_pendulum/">Inverted Double Pendulum</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../environments/mujoco/inverted_pendulum/">Inverted Pendulum</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../environments/mujoco/pusher/">Pusher</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../environments/mujoco/reacher/">Reacher</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../environments/mujoco/swimmer/">Swimmer</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../environments/mujoco/walker2d/">Walker2D</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="../../environments/atari/">Atari</a></li>
<li class="toctree-l1"><a class="reference internal" href="../../environments/third_party_environments/">External Environments</a></li>
</ul>
<p class="caption" role="heading"><span class="caption-text">Tutorials</span></p>
<ul>
<li class="toctree-l1 has-children"><a class="reference internal" href="../../tutorials/gymnasium_basics/">Gymnasium Basics Documentation Links</a><input class="toctree-checkbox" id="toctree-checkbox-8" name="toctree-checkbox-8" role="switch" type="checkbox"/><label for="toctree-checkbox-8"><div class="visually-hidden">Toggle navigation of Gymnasium Basics Documentation Links</div><i class="icon"><svg><use href="#svg-arrow-right"></use></svg></i></label><ul>
<li class="toctree-l2"><a class="reference internal" href="../../tutorials/gymnasium_basics/load_quadruped_model/">Load custom quadruped robot environments</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../tutorials/gymnasium_basics/handling_time_limits/">Handling Time Limits</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../tutorials/gymnasium_basics/implementing_custom_wrappers/">Implementing Custom Wrappers</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../tutorials/gymnasium_basics/environment_creation/">Make your own custom environment</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../tutorials/gymnasium_basics/vector_envs_tutorial/">Training A2C with Vector Envs and Domain Randomization</a></li>
</ul>
</li>
<li class="toctree-l1 has-children"><a class="reference internal" href="../../tutorials/training_agents/">Training Agents links in the Gymnasium Documentation</a><input class="toctree-checkbox" id="toctree-checkbox-9" name="toctree-checkbox-9" role="switch" type="checkbox"/><label for="toctree-checkbox-9"><div class="visually-hidden">Toggle navigation of Training Agents links in the Gymnasium Documentation</div><i class="icon"><svg><use href="#svg-arrow-right"></use></svg></i></label><ul>
<li class="toctree-l2"><a class="reference internal" href="../../tutorials/training_agents/reinforce_invpend_gym_v26/">Training using REINFORCE for Mujoco</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../tutorials/training_agents/blackjack_tutorial/">Solving Blackjack with Q-Learning</a></li>
<li class="toctree-l2"><a class="reference internal" href="../../tutorials/training_agents/FrozenLake_tuto/">Frozenlake benchmark</a></li>
</ul>
</li>
<li class="toctree-l1"><a class="reference internal" href="../../tutorials/third-party-tutorials/">Third-Party Tutorials</a></li>
</ul>
<p class="caption" role="heading"><span class="caption-text">Development</span></p>
<ul>
<li class="toctree-l1"><a class="reference external" href="https://github.com/Farama-Foundation/Gymnasium">Github</a></li>
<li class="toctree-l1"><a class="reference external" href="https://arxiv.org/abs/2407.17032">Paper</a></li>
<li class="toctree-l1"><a class="reference internal" href="../../gymnasium_release_notes/">Gymnasium Release Notes</a></li>
<li class="toctree-l1"><a class="reference internal" href="../../gym_release_notes/">Gym Release Notes</a></li>
<li class="toctree-l1"><a class="reference external" href="https://github.com/Farama-Foundation/Gymnasium/blob/main/docs/README.md">Contribute to the Docs</a></li>
</ul>
</div>
</div>
</div>
</div>
</aside>
<div class="main-container">
<div class="main">
<div class="content">
<div class="article-container">
<a href="#" class="back-to-top muted-link">
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24">
<path d="M13 20h-2V8l-5.5 5.5-1.42-1.42L12 4.16l7.92 7.92-1.42 1.42L13 8v12z"></path>
</svg>
<span>Back to top</span>
</a>
<div class="content-icon-container"><div class="edit-this-page">
<a class="muted-link" href="https://github.com/Farama-Foundation/Gymnasium/edit/main/docs/api/wrappers.md" title="Edit this page">
<svg aria-hidden="true" viewBox="0 0 24 24" stroke-width="1.5" stroke="currentColor" fill="none" stroke-linecap="round" stroke-linejoin="round">
<path stroke="none" d="M0 0h24v24H0z" fill="none"/>
<path d="M4 20h4l10.5 -10.5a1.5 1.5 0 0 0 -4 -4l-10.5 10.5v4" />
<line x1="13.5" y1="6.5" x2="17.5" y2="10.5" />
</svg>
<span class="visually-hidden">Edit this page</span>
</a>
</div><div class="theme-toggle-container theme-toggle-content">
<button class="theme-toggle" title="Toggle color theme">
<div class="visually-hidden">Toggle Light / Dark / Auto color theme</div>
<svg class="theme-icon-when-auto">
<use href="#svg-sun-half"></use>
</svg>
<svg class="theme-icon-when-dark">
<use href="#svg-moon"></use>
</svg>
<svg class="theme-icon-when-light">
<use href="#svg-sun"></use>
</svg>
</button>
</div>
<label class="toc-overlay-icon toc-content-icon" for="__toc">
<div class="visually-hidden">Toggle table of contents sidebar</div>
<i class="icon"><svg>
<use href="#svg-toc"></use>
</svg></i>
</label>
</div>
<article role="main">
<section class="tex2jax_ignore mathjax_ignore" id="wrappers">
<h1>Wrappers<a class="headerlink" href="#wrappers" title="Link to this heading"></a></h1>
<div class="toctree-wrapper compound">
</div>
<p id="module-gymnasium.wrappers">Wrappers are a convenient way to modify an existing environment without having to alter the underlying code directly.</p>
<p>Using wrappers will allow you to avoid a lot of boilerplate code and make your environment more modular.
Importantly wrappers can be chained to combine their effects and most environments that are generated via
<a class="reference internal" href="../registry/#gymnasium.make" title="gymnasium.make"><code class="xref py py-meth docutils literal notranslate"><span class="pre">gymnasium.make()</span></code></a> will already be wrapped by default.</p>
<p>In order to wrap an environment, you must first initialize a base environment. Then you can pass this environment along
with (possibly optional) parameters to the wrappers constructor.</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="kn">import</span><span class="w"> </span><span class="nn">gymnasium</span><span class="w"> </span><span class="k">as</span><span class="w"> </span><span class="nn">gym</span>
<span class="gp">&gt;&gt;&gt; </span><span class="kn">from</span><span class="w"> </span><span class="nn">gymnasium.wrappers</span><span class="w"> </span><span class="kn">import</span> <span class="n">RescaleAction</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">base_env</span> <span class="o">=</span> <span class="n">gym</span><span class="o">.</span><span class="n">make</span><span class="p">(</span><span class="s2">&quot;Hopper-v4&quot;</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">base_env</span><span class="o">.</span><span class="n">action_space</span>
<span class="go">Box(-1.0, 1.0, (3,), float32)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">wrapped_env</span> <span class="o">=</span> <span class="n">RescaleAction</span><span class="p">(</span><span class="n">base_env</span><span class="p">,</span> <span class="n">min_action</span><span class="o">=</span><span class="mi">0</span><span class="p">,</span> <span class="n">max_action</span><span class="o">=</span><span class="mi">1</span><span class="p">)</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">wrapped_env</span><span class="o">.</span><span class="n">action_space</span>
<span class="go">Box(0.0, 1.0, (3,), float32)</span>
</pre></div>
</div>
<p>You can access the environment underneath the <strong>first</strong> wrapper by using the <a class="reference internal" href="#gymnasium.Wrapper.env" title="gymnasium.Wrapper.env"><code class="xref py py-attr docutils literal notranslate"><span class="pre">gymnasium.Wrapper.env</span></code></a> attribute.
As the <a class="reference internal" href="#gymnasium.Wrapper" title="gymnasium.Wrapper"><code class="xref py py-class docutils literal notranslate"><span class="pre">gymnasium.Wrapper</span></code></a> class inherits from <a class="reference internal" href="../env/#gymnasium.Env" title="gymnasium.Env"><code class="xref py py-class docutils literal notranslate"><span class="pre">gymnasium.Env</span></code></a> then <a class="reference internal" href="#gymnasium.Wrapper.env" title="gymnasium.Wrapper.env"><code class="xref py py-attr docutils literal notranslate"><span class="pre">gymnasium.Wrapper.env</span></code></a> can be another wrapper.</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">wrapped_env</span>
<span class="go">&lt;RescaleAction&lt;TimeLimit&lt;OrderEnforcing&lt;PassiveEnvChecker&lt;HopperEnv&lt;Hopper-v4&gt;&gt;&gt;&gt;&gt;&gt;</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">wrapped_env</span><span class="o">.</span><span class="n">env</span>
<span class="go">&lt;TimeLimit&lt;OrderEnforcing&lt;PassiveEnvChecker&lt;HopperEnv&lt;Hopper-v4&gt;&gt;&gt;&gt;&gt;</span>
</pre></div>
</div>
<p>If you want to get to the environment underneath <strong>all</strong> of the layers of wrappers, you can use the
<a class="reference internal" href="#gymnasium.Wrapper.unwrapped" title="gymnasium.Wrapper.unwrapped"><code class="xref py py-attr docutils literal notranslate"><span class="pre">gymnasium.Wrapper.unwrapped</span></code></a> attribute.
If the environment is already a bare environment, the <a class="reference internal" href="#gymnasium.Wrapper.unwrapped" title="gymnasium.Wrapper.unwrapped"><code class="xref py py-attr docutils literal notranslate"><span class="pre">gymnasium.Wrapper.unwrapped</span></code></a> attribute will just return itself.</p>
<div class="doctest highlight-default notranslate"><div class="highlight"><pre><span></span><span class="gp">&gt;&gt;&gt; </span><span class="n">wrapped_env</span>
<span class="go">&lt;RescaleAction&lt;TimeLimit&lt;OrderEnforcing&lt;PassiveEnvChecker&lt;HopperEnv&lt;Hopper-v4&gt;&gt;&gt;&gt;&gt;&gt;</span>
<span class="gp">&gt;&gt;&gt; </span><span class="n">wrapped_env</span><span class="o">.</span><span class="n">unwrapped</span>
<span class="go">&lt;gymnasium.envs.mujoco.hopper_v4.HopperEnv object at 0x7fbb5efd0490&gt;</span>
</pre></div>
</div>
<p>There are three common things you might want a wrapper to do:</p>
<ul class="simple">
<li><p>Transform actions before applying them to the base environment</p></li>
<li><p>Transform observations that are returned by the base environment</p></li>
<li><p>Transform rewards that are returned by the base environment</p></li>
</ul>
<p>Such wrappers can be easily implemented by inheriting from <a class="reference internal" href="action_wrappers/#gymnasium.ActionWrapper" title="gymnasium.ActionWrapper"><code class="xref py py-class docutils literal notranslate"><span class="pre">gymnasium.ActionWrapper</span></code></a>,
<a class="reference internal" href="observation_wrappers/#gymnasium.ObservationWrapper" title="gymnasium.ObservationWrapper"><code class="xref py py-class docutils literal notranslate"><span class="pre">gymnasium.ObservationWrapper</span></code></a>, or <a class="reference internal" href="reward_wrappers/#gymnasium.RewardWrapper" title="gymnasium.RewardWrapper"><code class="xref py py-class docutils literal notranslate"><span class="pre">gymnasium.RewardWrapper</span></code></a> and implementing the respective transformation.
If you need a wrapper to do more complicated tasks, you can inherit from the <a class="reference internal" href="#gymnasium.Wrapper" title="gymnasium.Wrapper"><code class="xref py py-class docutils literal notranslate"><span class="pre">gymnasium.Wrapper</span></code></a> class directly.</p>
<p>If youd like to implement your own custom wrapper, check out <a class="reference external" href="../../tutorials/gymnasium_basics/implementing_custom_wrappers">the corresponding tutorial</a>.</p>
<dl class="py class">
<dt class="sig sig-object py" id="gymnasium.Wrapper">
<em class="property"><span class="pre">class</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">gymnasium.</span></span><span class="sig-name descname"><span class="pre">Wrapper</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">env</span></span><span class="p"><span class="pre">:</span></span><span class="w"> </span><span class="n"><a class="reference internal" href="../env/#gymnasium.Env" title="gymnasium.core.Env"><span class="pre">Env</span></a><span class="p"><span class="pre">[</span></span><span class="pre">ObsType</span><span class="p"><span class="pre">,</span></span><span class="w"> </span><span class="pre">ActType</span><span class="p"><span class="pre">]</span></span></span></em><span class="sig-paren">)</span><a class="reference internal" href="../../_modules/gymnasium/core/#Wrapper"><span class="viewcode-link"><span class="pre">[source]</span></span></a><a class="headerlink" href="#gymnasium.Wrapper" title="Link to this definition"></a></dt>
<dd><p>Wraps a <a class="reference internal" href="../env/#gymnasium.Env" title="gymnasium.Env"><code class="xref py py-class docutils literal notranslate"><span class="pre">gymnasium.Env</span></code></a> to allow a modular transformation of the <a class="reference internal" href="#gymnasium.Wrapper.step" title="gymnasium.Wrapper.step"><code class="xref py py-meth docutils literal notranslate"><span class="pre">step()</span></code></a> and <a class="reference internal" href="#gymnasium.Wrapper.reset" title="gymnasium.Wrapper.reset"><code class="xref py py-meth docutils literal notranslate"><span class="pre">reset()</span></code></a> methods.</p>
<p>This class is the base class of all wrappers to change the behavior of the underlying environment.
Wrappers that inherit from this class can modify the <a class="reference internal" href="#gymnasium.Wrapper.action_space" title="gymnasium.Wrapper.action_space"><code class="xref py py-attr docutils literal notranslate"><span class="pre">action_space</span></code></a>, <a class="reference internal" href="#gymnasium.Wrapper.observation_space" title="gymnasium.Wrapper.observation_space"><code class="xref py py-attr docutils literal notranslate"><span class="pre">observation_space</span></code></a>
and <a class="reference internal" href="#gymnasium.Wrapper.metadata" title="gymnasium.Wrapper.metadata"><code class="xref py py-attr docutils literal notranslate"><span class="pre">metadata</span></code></a> attributes, without changing the underlying environments attributes.
Moreover, the behavior of the <a class="reference internal" href="#gymnasium.Wrapper.step" title="gymnasium.Wrapper.step"><code class="xref py py-meth docutils literal notranslate"><span class="pre">step()</span></code></a> and <a class="reference internal" href="#gymnasium.Wrapper.reset" title="gymnasium.Wrapper.reset"><code class="xref py py-meth docutils literal notranslate"><span class="pre">reset()</span></code></a> methods can be changed by these wrappers.</p>
<p>Some attributes (<a class="reference internal" href="../registry/#gymnasium.spec" title="gymnasium.spec"><code class="xref py py-attr docutils literal notranslate"><span class="pre">spec</span></code></a>, <code class="xref py py-attr docutils literal notranslate"><span class="pre">render_mode</span></code>, <a class="reference internal" href="#gymnasium.Wrapper.np_random" title="gymnasium.Wrapper.np_random"><code class="xref py py-attr docutils literal notranslate"><span class="pre">np_random</span></code></a>) will point back to the wrappers environment
(i.e. to the corresponding attributes of <a class="reference internal" href="#gymnasium.Wrapper.env" title="gymnasium.Wrapper.env"><code class="xref py py-attr docutils literal notranslate"><span class="pre">env</span></code></a>).</p>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>If you inherit from <a class="reference internal" href="#gymnasium.Wrapper" title="gymnasium.Wrapper"><code class="xref py py-class docutils literal notranslate"><span class="pre">Wrapper</span></code></a>, dont forget to call <code class="docutils literal notranslate"><span class="pre">super().__init__(env)</span></code></p>
</div>
<dl class="field-list simple">
<dt class="field-odd">Parameters<span class="colon">:</span></dt>
<dd class="field-odd"><p><strong>env</strong> The environment to wrap</p>
</dd>
</dl>
</dd></dl>
<section id="methods">
<h2>Methods<a class="headerlink" href="#methods" title="Link to this heading"></a></h2>
<dl class="py method">
<dt class="sig sig-object py" id="gymnasium.Wrapper.step">
<span class="sig-prename descclassname"><span class="pre">Wrapper.</span></span><span class="sig-name descname"><span class="pre">step</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">action</span></span><span class="p"><span class="pre">:</span></span><span class="w"> </span><span class="n"><span class="pre">WrapperActType</span></span></em><span class="sig-paren">)</span> <span class="sig-return"><span class="sig-return-icon">&#x2192;</span> <span class="sig-return-typehint"><span class="pre">tuple</span><span class="p"><span class="pre">[</span></span><span class="pre">WrapperObsType</span><span class="p"><span class="pre">,</span></span><span class="w"> </span><span class="pre">SupportsFloat</span><span class="p"><span class="pre">,</span></span><span class="w"> </span><span class="pre">bool</span><span class="p"><span class="pre">,</span></span><span class="w"> </span><span class="pre">bool</span><span class="p"><span class="pre">,</span></span><span class="w"> </span><span class="pre">dict</span><span class="p"><span class="pre">[</span></span><span class="pre">str</span><span class="p"><span class="pre">,</span></span><span class="w"> </span><span class="pre">Any</span><span class="p"><span class="pre">]</span></span><span class="p"><span class="pre">]</span></span></span></span><a class="reference internal" href="../../_modules/gymnasium/core/#Wrapper.step"><span class="viewcode-link"><span class="pre">[source]</span></span></a><a class="headerlink" href="#gymnasium.Wrapper.step" title="Link to this definition"></a></dt>
<dd><p>Uses the <a class="reference internal" href="#gymnasium.Wrapper.step" title="gymnasium.Wrapper.step"><code class="xref py py-meth docutils literal notranslate"><span class="pre">step()</span></code></a> of the <a class="reference internal" href="#gymnasium.Wrapper.env" title="gymnasium.Wrapper.env"><code class="xref py py-attr docutils literal notranslate"><span class="pre">env</span></code></a> that can be overwritten to change the returned data.</p>
</dd></dl>
<dl class="py method">
<dt class="sig sig-object py" id="gymnasium.Wrapper.reset">
<span class="sig-prename descclassname"><span class="pre">Wrapper.</span></span><span class="sig-name descname"><span class="pre">reset</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="o"><span class="pre">*</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">seed</span></span><span class="p"><span class="pre">:</span></span><span class="w"> </span><span class="n"><span class="pre">int</span><span class="w"> </span><span class="p"><span class="pre">|</span></span><span class="w"> </span><span class="pre">None</span></span><span class="w"> </span><span class="o"><span class="pre">=</span></span><span class="w"> </span><span class="default_value"><span class="pre">None</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">options</span></span><span class="p"><span class="pre">:</span></span><span class="w"> </span><span class="n"><span class="pre">dict</span><span class="p"><span class="pre">[</span></span><span class="pre">str</span><span class="p"><span class="pre">,</span></span><span class="w"> </span><span class="pre">Any</span><span class="p"><span class="pre">]</span></span><span class="w"> </span><span class="p"><span class="pre">|</span></span><span class="w"> </span><span class="pre">None</span></span><span class="w"> </span><span class="o"><span class="pre">=</span></span><span class="w"> </span><span class="default_value"><span class="pre">None</span></span></em><span class="sig-paren">)</span> <span class="sig-return"><span class="sig-return-icon">&#x2192;</span> <span class="sig-return-typehint"><span class="pre">tuple</span><span class="p"><span class="pre">[</span></span><span class="pre">WrapperObsType</span><span class="p"><span class="pre">,</span></span><span class="w"> </span><span class="pre">dict</span><span class="p"><span class="pre">[</span></span><span class="pre">str</span><span class="p"><span class="pre">,</span></span><span class="w"> </span><span class="pre">Any</span><span class="p"><span class="pre">]</span></span><span class="p"><span class="pre">]</span></span></span></span><a class="reference internal" href="../../_modules/gymnasium/core/#Wrapper.reset"><span class="viewcode-link"><span class="pre">[source]</span></span></a><a class="headerlink" href="#gymnasium.Wrapper.reset" title="Link to this definition"></a></dt>
<dd><p>Uses the <a class="reference internal" href="#gymnasium.Wrapper.reset" title="gymnasium.Wrapper.reset"><code class="xref py py-meth docutils literal notranslate"><span class="pre">reset()</span></code></a> of the <a class="reference internal" href="#gymnasium.Wrapper.env" title="gymnasium.Wrapper.env"><code class="xref py py-attr docutils literal notranslate"><span class="pre">env</span></code></a> that can be overwritten to change the returned data.</p>
</dd></dl>
<dl class="py method">
<dt class="sig sig-object py" id="gymnasium.Wrapper.render">
<span class="sig-prename descclassname"><span class="pre">Wrapper.</span></span><span class="sig-name descname"><span class="pre">render</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span> <span class="sig-return"><span class="sig-return-icon">&#x2192;</span> <span class="sig-return-typehint"><span class="pre">RenderFrame</span><span class="w"> </span><span class="p"><span class="pre">|</span></span><span class="w"> </span><span class="pre">list</span><span class="p"><span class="pre">[</span></span><span class="pre">RenderFrame</span><span class="p"><span class="pre">]</span></span><span class="w"> </span><span class="p"><span class="pre">|</span></span><span class="w"> </span><span class="pre">None</span></span></span><a class="reference internal" href="../../_modules/gymnasium/core/#Wrapper.render"><span class="viewcode-link"><span class="pre">[source]</span></span></a><a class="headerlink" href="#gymnasium.Wrapper.render" title="Link to this definition"></a></dt>
<dd><p>Uses the <a class="reference internal" href="#gymnasium.Wrapper.render" title="gymnasium.Wrapper.render"><code class="xref py py-meth docutils literal notranslate"><span class="pre">render()</span></code></a> of the <a class="reference internal" href="#gymnasium.Wrapper.env" title="gymnasium.Wrapper.env"><code class="xref py py-attr docutils literal notranslate"><span class="pre">env</span></code></a> that can be overwritten to change the returned data.</p>
</dd></dl>
<dl class="py method">
<dt class="sig sig-object py" id="gymnasium.Wrapper.close">
<span class="sig-prename descclassname"><span class="pre">Wrapper.</span></span><span class="sig-name descname"><span class="pre">close</span></span><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="reference internal" href="../../_modules/gymnasium/core/#Wrapper.close"><span class="viewcode-link"><span class="pre">[source]</span></span></a><a class="headerlink" href="#gymnasium.Wrapper.close" title="Link to this definition"></a></dt>
<dd><p>Closes the wrapper and <a class="reference internal" href="#gymnasium.Wrapper.env" title="gymnasium.Wrapper.env"><code class="xref py py-attr docutils literal notranslate"><span class="pre">env</span></code></a>.</p>
</dd></dl>
<dl class="py method">
<dt class="sig sig-object py" id="gymnasium.Wrapper.wrapper_spec">
<em class="property"><span class="pre">classmethod</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">Wrapper.</span></span><span class="sig-name descname"><span class="pre">wrapper_spec</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="o"><span class="pre">**</span></span><span class="n"><span class="pre">kwargs</span></span><span class="p"><span class="pre">:</span></span><span class="w"> </span><span class="n"><span class="pre">Any</span></span></em><span class="sig-paren">)</span> <span class="sig-return"><span class="sig-return-icon">&#x2192;</span> <span class="sig-return-typehint"><a class="reference internal" href="../registry/#gymnasium.envs.registration.WrapperSpec" title="gymnasium.envs.registration.WrapperSpec"><span class="pre">WrapperSpec</span></a></span></span><a class="reference internal" href="../../_modules/gymnasium/core/#Wrapper.wrapper_spec"><span class="viewcode-link"><span class="pre">[source]</span></span></a><a class="headerlink" href="#gymnasium.Wrapper.wrapper_spec" title="Link to this definition"></a></dt>
<dd><p>Generates a <cite>WrapperSpec</cite> for the wrappers.</p>
</dd></dl>
<dl class="py method">
<dt class="sig sig-object py" id="gymnasium.Wrapper.get_wrapper_attr">
<span class="sig-prename descclassname"><span class="pre">Wrapper.</span></span><span class="sig-name descname"><span class="pre">get_wrapper_attr</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">name</span></span><span class="p"><span class="pre">:</span></span><span class="w"> </span><span class="n"><span class="pre">str</span></span></em><span class="sig-paren">)</span> <span class="sig-return"><span class="sig-return-icon">&#x2192;</span> <span class="sig-return-typehint"><span class="pre">Any</span></span></span><a class="reference internal" href="../../_modules/gymnasium/core/#Wrapper.get_wrapper_attr"><span class="viewcode-link"><span class="pre">[source]</span></span></a><a class="headerlink" href="#gymnasium.Wrapper.get_wrapper_attr" title="Link to this definition"></a></dt>
<dd><p>Gets an attribute from the wrapper and lower environments if <cite>name</cite> doesnt exist in this object.</p>
<dl class="field-list simple">
<dt class="field-odd">Parameters<span class="colon">:</span></dt>
<dd class="field-odd"><p><strong>name</strong> The variable name to get</p>
</dd>
<dt class="field-even">Returns<span class="colon">:</span></dt>
<dd class="field-even"><p><strong>The variable with name in wrapper or lower environments</strong></p>
</dd>
</dl>
</dd></dl>
<dl class="py method">
<dt class="sig sig-object py" id="gymnasium.Wrapper.set_wrapper_attr">
<span class="sig-prename descclassname"><span class="pre">Wrapper.</span></span><span class="sig-name descname"><span class="pre">set_wrapper_attr</span></span><span class="sig-paren">(</span><em class="sig-param"><span class="n"><span class="pre">name</span></span><span class="p"><span class="pre">:</span></span><span class="w"> </span><span class="n"><span class="pre">str</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">value</span></span><span class="p"><span class="pre">:</span></span><span class="w"> </span><span class="n"><span class="pre">Any</span></span></em>, <em class="sig-param"><span class="o"><span class="pre">*</span></span></em>, <em class="sig-param"><span class="n"><span class="pre">force</span></span><span class="p"><span class="pre">:</span></span><span class="w"> </span><span class="n"><span class="pre">bool</span></span><span class="w"> </span><span class="o"><span class="pre">=</span></span><span class="w"> </span><span class="default_value"><span class="pre">True</span></span></em><span class="sig-paren">)</span> <span class="sig-return"><span class="sig-return-icon">&#x2192;</span> <span class="sig-return-typehint"><span class="pre">bool</span></span></span><a class="reference internal" href="../../_modules/gymnasium/core/#Wrapper.set_wrapper_attr"><span class="viewcode-link"><span class="pre">[source]</span></span></a><a class="headerlink" href="#gymnasium.Wrapper.set_wrapper_attr" title="Link to this definition"></a></dt>
<dd><p>Sets an attribute on this wrapper or lower environment if <cite>name</cite> is already defined.</p>
<dl class="field-list simple">
<dt class="field-odd">Parameters<span class="colon">:</span></dt>
<dd class="field-odd"><ul class="simple">
<li><p><strong>name</strong> The variable name</p></li>
<li><p><strong>value</strong> The new variable value</p></li>
<li><p><strong>force</strong> Whether to create the attribute on this wrapper if it does not exists on the
lower environment instead of raising an exception</p></li>
</ul>
</dd>
<dt class="field-even">Returns<span class="colon">:</span></dt>
<dd class="field-even"><p><strong>If the variable has been set in this or a lower wrapper.</strong></p>
</dd>
</dl>
</dd></dl>
</section>
<section id="attributes">
<h2>Attributes<a class="headerlink" href="#attributes" title="Link to this heading"></a></h2>
<dl class="py attribute">
<dt class="sig sig-object py" id="gymnasium.Wrapper.env">
<span class="sig-prename descclassname"><span class="pre">Wrapper.</span></span><span class="sig-name descname"><span class="pre">env</span></span><a class="headerlink" href="#gymnasium.Wrapper.env" title="Link to this definition"></a></dt>
<dd><p>The environment (one level underneath) this wrapper.</p>
<p>This may itself be a wrapped environment. To obtain the environment underneath all layers of wrappers, use <a class="reference internal" href="#gymnasium.Wrapper.unwrapped" title="gymnasium.Wrapper.unwrapped"><code class="xref py py-attr docutils literal notranslate"><span class="pre">gymnasium.Wrapper.unwrapped</span></code></a>.</p>
</dd></dl>
<dl class="py property">
<dt class="sig sig-object py" id="gymnasium.Wrapper.action_space">
<em class="property"><span class="pre">property</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">Wrapper.</span></span><span class="sig-name descname"><span class="pre">action_space</span></span><em class="property"><span class="p"><span class="pre">:</span></span><span class="w"> </span><a class="reference internal" href="../spaces/#gymnasium.spaces.Space" title="gymnasium.spaces.Space"><span class="pre">spaces.Space</span></a><span class="p"><span class="pre">[</span></span><span class="pre">ActType</span><span class="p"><span class="pre">]</span></span><span class="w"> </span><span class="p"><span class="pre">|</span></span><span class="w"> </span><a class="reference internal" href="../spaces/#gymnasium.spaces.Space" title="gymnasium.spaces.Space"><span class="pre">spaces.Space</span></a><span class="p"><span class="pre">[</span></span><span class="pre">WrapperActType</span><span class="p"><span class="pre">]</span></span></em><a class="headerlink" href="#gymnasium.Wrapper.action_space" title="Link to this definition"></a></dt>
<dd><p>Return the <a class="reference internal" href="../env/#gymnasium.Env" title="gymnasium.Env"><code class="xref py py-attr docutils literal notranslate"><span class="pre">Env</span></code></a> <a class="reference internal" href="#gymnasium.Wrapper.action_space" title="gymnasium.Wrapper.action_space"><code class="xref py py-attr docutils literal notranslate"><span class="pre">action_space</span></code></a> unless overwritten then the wrapper <a class="reference internal" href="#gymnasium.Wrapper.action_space" title="gymnasium.Wrapper.action_space"><code class="xref py py-attr docutils literal notranslate"><span class="pre">action_space</span></code></a> is used.</p>
</dd></dl>
<dl class="py property">
<dt class="sig sig-object py" id="gymnasium.Wrapper.observation_space">
<em class="property"><span class="pre">property</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">Wrapper.</span></span><span class="sig-name descname"><span class="pre">observation_space</span></span><em class="property"><span class="p"><span class="pre">:</span></span><span class="w"> </span><a class="reference internal" href="../spaces/#gymnasium.spaces.Space" title="gymnasium.spaces.Space"><span class="pre">spaces.Space</span></a><span class="p"><span class="pre">[</span></span><span class="pre">ObsType</span><span class="p"><span class="pre">]</span></span><span class="w"> </span><span class="p"><span class="pre">|</span></span><span class="w"> </span><a class="reference internal" href="../spaces/#gymnasium.spaces.Space" title="gymnasium.spaces.Space"><span class="pre">spaces.Space</span></a><span class="p"><span class="pre">[</span></span><span class="pre">WrapperObsType</span><span class="p"><span class="pre">]</span></span></em><a class="headerlink" href="#gymnasium.Wrapper.observation_space" title="Link to this definition"></a></dt>
<dd><p>Return the <a class="reference internal" href="../env/#gymnasium.Env" title="gymnasium.Env"><code class="xref py py-attr docutils literal notranslate"><span class="pre">Env</span></code></a> <a class="reference internal" href="#gymnasium.Wrapper.observation_space" title="gymnasium.Wrapper.observation_space"><code class="xref py py-attr docutils literal notranslate"><span class="pre">observation_space</span></code></a> unless overwritten then the wrapper <a class="reference internal" href="#gymnasium.Wrapper.observation_space" title="gymnasium.Wrapper.observation_space"><code class="xref py py-attr docutils literal notranslate"><span class="pre">observation_space</span></code></a> is used.</p>
</dd></dl>
<dl class="py property">
<dt class="sig sig-object py" id="gymnasium.Wrapper.spec">
<em class="property"><span class="pre">property</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">Wrapper.</span></span><span class="sig-name descname"><span class="pre">spec</span></span><em class="property"><span class="p"><span class="pre">:</span></span><span class="w"> </span><a class="reference internal" href="../registry/#gymnasium.envs.registration.EnvSpec" title="gymnasium.envs.registration.EnvSpec"><span class="pre">EnvSpec</span></a><span class="w"> </span><span class="p"><span class="pre">|</span></span><span class="w"> </span><span class="pre">None</span></em><a class="headerlink" href="#gymnasium.Wrapper.spec" title="Link to this definition"></a></dt>
<dd><p>Returns the <a class="reference internal" href="../env/#gymnasium.Env" title="gymnasium.Env"><code class="xref py py-attr docutils literal notranslate"><span class="pre">Env</span></code></a> <a class="reference internal" href="../registry/#gymnasium.spec" title="gymnasium.spec"><code class="xref py py-attr docutils literal notranslate"><span class="pre">spec</span></code></a> attribute with the <cite>WrapperSpec</cite> if the wrapper inherits from <cite>EzPickle</cite>.</p>
</dd></dl>
<dl class="py property">
<dt class="sig sig-object py" id="gymnasium.Wrapper.metadata">
<em class="property"><span class="pre">property</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">Wrapper.</span></span><span class="sig-name descname"><span class="pre">metadata</span></span><em class="property"><span class="p"><span class="pre">:</span></span><span class="w"> </span><span class="pre">dict</span><span class="p"><span class="pre">[</span></span><span class="pre">str</span><span class="p"><span class="pre">,</span></span><span class="w"> </span><span class="pre">Any</span><span class="p"><span class="pre">]</span></span></em><a class="headerlink" href="#gymnasium.Wrapper.metadata" title="Link to this definition"></a></dt>
<dd><p>Returns the <a class="reference internal" href="../env/#gymnasium.Env" title="gymnasium.Env"><code class="xref py py-attr docutils literal notranslate"><span class="pre">Env</span></code></a> <a class="reference internal" href="#gymnasium.Wrapper.metadata" title="gymnasium.Wrapper.metadata"><code class="xref py py-attr docutils literal notranslate"><span class="pre">metadata</span></code></a>.</p>
</dd></dl>
<dl class="py property">
<dt class="sig sig-object py" id="gymnasium.Wrapper.np_random">
<em class="property"><span class="pre">property</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">Wrapper.</span></span><span class="sig-name descname"><span class="pre">np_random</span></span><em class="property"><span class="p"><span class="pre">:</span></span><span class="w"> </span><span class="pre">Generator</span></em><a class="headerlink" href="#gymnasium.Wrapper.np_random" title="Link to this definition"></a></dt>
<dd><p>Returns the <a class="reference internal" href="../env/#gymnasium.Env" title="gymnasium.Env"><code class="xref py py-attr docutils literal notranslate"><span class="pre">Env</span></code></a> <a class="reference internal" href="#gymnasium.Wrapper.np_random" title="gymnasium.Wrapper.np_random"><code class="xref py py-attr docutils literal notranslate"><span class="pre">np_random</span></code></a> attribute.</p>
</dd></dl>
<dl class="py property">
<dt class="sig sig-object py" id="gymnasium.Wrapper.np_random_seed">
<em class="property"><span class="pre">property</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">Wrapper.</span></span><span class="sig-name descname"><span class="pre">np_random_seed</span></span><em class="property"><span class="p"><span class="pre">:</span></span><span class="w"> </span><span class="pre">int</span><span class="w"> </span><span class="p"><span class="pre">|</span></span><span class="w"> </span><span class="pre">None</span></em><a class="headerlink" href="#gymnasium.Wrapper.np_random_seed" title="Link to this definition"></a></dt>
<dd><p>Returns the base environments <a class="reference internal" href="#gymnasium.Wrapper.np_random_seed" title="gymnasium.Wrapper.np_random_seed"><code class="xref py py-attr docutils literal notranslate"><span class="pre">np_random_seed</span></code></a>.</p>
</dd></dl>
<dl class="py property">
<dt class="sig sig-object py" id="gymnasium.Wrapper.unwrapped">
<em class="property"><span class="pre">property</span><span class="w"> </span></em><span class="sig-prename descclassname"><span class="pre">Wrapper.</span></span><span class="sig-name descname"><span class="pre">unwrapped</span></span><em class="property"><span class="p"><span class="pre">:</span></span><span class="w"> </span><a class="reference internal" href="../env/#gymnasium.Env" title="gymnasium.core.Env"><span class="pre">Env</span></a><span class="p"><span class="pre">[</span></span><span class="pre">ObsType</span><span class="p"><span class="pre">,</span></span><span class="w"> </span><span class="pre">ActType</span><span class="p"><span class="pre">]</span></span></em><a class="headerlink" href="#gymnasium.Wrapper.unwrapped" title="Link to this definition"></a></dt>
<dd><p>Returns the base environment of the wrapper.</p>
<p>This will be the bare <a class="reference internal" href="../env/#gymnasium.Env" title="gymnasium.Env"><code class="xref py py-class docutils literal notranslate"><span class="pre">gymnasium.Env</span></code></a> environment, underneath all layers of wrappers.</p>
</dd></dl>
</section>
</section>
</article>
</div>
<footer>
<div class="related-pages">
<a class="next-page" href="table/">
<div class="page-info">
<div class="context">
<span>Next</span>
</div>
<div class="title">List of Wrappers</div>
</div>
<svg class="furo-related-icon">
<use href="#svg-arrow-right"></use>
</svg>
</a>
<a class="prev-page" href="../spaces/utils/">
<svg class="furo-related-icon">
<use href="#svg-arrow-right"></use>
</svg>
<div class="page-info">
<div class="context">
<span>Previous</span>
</div>
<div class="title">Spaces Utils</div>
</div>
</a>
</div>
<div class="bottom-of-page">
<div class="left-details">
<div class="copyright">
Copyright &#169; 2025 Farama Foundation
</div>
<!--
Made with <a href="https://www.sphinx-doc.org/">Sphinx</a> and <a class="muted-link" href="https://pradyunsg.me">@pradyunsg</a>'s
<a href="https://github.com/pradyunsg/furo">Furo</a>
-->
</div>
<div class="right-details">
<div class="icons">
<a class="muted-link" href="https://github.com/Farama-Foundation/Gymnasium/"
aria-label="On GitHub">
<svg stroke="currentColor" fill="currentColor" stroke-width="0" viewBox="0 0 16 16">
<path fill-rule="evenodd"
d="M8 0C3.58 0 0 3.58 0 8c0 3.54 2.29 6.53 5.47 7.59.4.07.55-.17.55-.38 0-.19-.01-.82-.01-1.49-2.01.37-2.53-.49-2.69-.94-.09-.23-.48-.94-.82-1.13-.28-.15-.68-.52-.01-.53.63-.01 1.08.58 1.23.82.72 1.21 1.87.87 2.33.66.07-.52.28-.87.51-1.07-1.78-.2-3.64-.89-3.64-3.95 0-.87.31-1.59.82-2.15-.08-.2-.36-1.02.08-2.12 0 0 .67-.21 2.2.82.64-.18 1.32-.27 2-.27.68 0 1.36.09 2 .27 1.53-1.04 2.2-.82 2.2-.82.44 1.1.16 1.92.08 2.12.51.56.82 1.27.82 2.15 0 3.07-1.87 3.75-3.65 3.95.29.25.54.73.54 1.48 0 1.07-.01 1.93-.01 2.2 0 .21.15.46.55.38A8.013 8.013 0 0 0 16 8c0-4.42-3.58-8-8-8z">
</path>
</svg>
</a>
</div>
</div>
</div>
</footer>
</div>
<aside class="toc-drawer">
<div class="toc-sticky toc-scroll">
<div class="toc-title-container">
<span class="toc-title">
On this page
</span>
</div>
<div class="toc-tree-container">
<div class="toc-tree">
<ul>
<li><a class="reference internal" href="#">Wrappers</a><ul>
<li><a class="reference internal" href="#gymnasium.Wrapper"><code class="docutils literal notranslate"><span class="pre">Wrapper</span></code></a></li>
<li><a class="reference internal" href="#methods">Methods</a><ul>
<li><a class="reference internal" href="#gymnasium.Wrapper.step"><code class="docutils literal notranslate"><span class="pre">Wrapper.step()</span></code></a></li>
<li><a class="reference internal" href="#gymnasium.Wrapper.reset"><code class="docutils literal notranslate"><span class="pre">Wrapper.reset()</span></code></a></li>
<li><a class="reference internal" href="#gymnasium.Wrapper.render"><code class="docutils literal notranslate"><span class="pre">Wrapper.render()</span></code></a></li>
<li><a class="reference internal" href="#gymnasium.Wrapper.close"><code class="docutils literal notranslate"><span class="pre">Wrapper.close()</span></code></a></li>
<li><a class="reference internal" href="#gymnasium.Wrapper.wrapper_spec"><code class="docutils literal notranslate"><span class="pre">Wrapper.wrapper_spec()</span></code></a></li>
<li><a class="reference internal" href="#gymnasium.Wrapper.get_wrapper_attr"><code class="docutils literal notranslate"><span class="pre">Wrapper.get_wrapper_attr()</span></code></a></li>
<li><a class="reference internal" href="#gymnasium.Wrapper.set_wrapper_attr"><code class="docutils literal notranslate"><span class="pre">Wrapper.set_wrapper_attr()</span></code></a></li>
</ul>
</li>
<li><a class="reference internal" href="#attributes">Attributes</a><ul>
<li><a class="reference internal" href="#gymnasium.Wrapper.env"><code class="docutils literal notranslate"><span class="pre">Wrapper.env</span></code></a></li>
<li><a class="reference internal" href="#gymnasium.Wrapper.action_space"><code class="docutils literal notranslate"><span class="pre">Wrapper.action_space</span></code></a></li>
<li><a class="reference internal" href="#gymnasium.Wrapper.observation_space"><code class="docutils literal notranslate"><span class="pre">Wrapper.observation_space</span></code></a></li>
<li><a class="reference internal" href="#gymnasium.Wrapper.spec"><code class="docutils literal notranslate"><span class="pre">Wrapper.spec</span></code></a></li>
<li><a class="reference internal" href="#gymnasium.Wrapper.metadata"><code class="docutils literal notranslate"><span class="pre">Wrapper.metadata</span></code></a></li>
<li><a class="reference internal" href="#gymnasium.Wrapper.np_random"><code class="docutils literal notranslate"><span class="pre">Wrapper.np_random</span></code></a></li>
<li><a class="reference internal" href="#gymnasium.Wrapper.np_random_seed"><code class="docutils literal notranslate"><span class="pre">Wrapper.np_random_seed</span></code></a></li>
<li><a class="reference internal" href="#gymnasium.Wrapper.unwrapped"><code class="docutils literal notranslate"><span class="pre">Wrapper.unwrapped</span></code></a></li>
</ul>
</li>
</ul>
</li>
</ul>
</div>
</div>
</div>
</aside>
</div>
</div>
</div>
<script>
const toggleMenu = () => {
const menuBtn = document.querySelector(".farama-header-menu__btn");
const menuContainer = document.querySelector(".farama-header-menu-container");
if (document.querySelector(".farama-header-menu").classList.contains("active")) {
menuBtn.setAttribute("aria-expanded", "false");
menuContainer.setAttribute("aria-hidden", "true");
} else {
menuBtn.setAttribute("aria-expanded", "true");
menuContainer.setAttribute("aria-hidden", "false");
}
document.querySelector(".farama-header-menu").classList.toggle("active");
}
document.querySelector(".farama-header-menu__btn").addEventListener("click", toggleMenu);
document.getElementById("farama-close-menu").addEventListener("click", toggleMenu);
</script>
<script async src="https://www.googletagmanager.com/gtag/js?id=G-6H9C8TWXZ8"></script>
<script>
const enableGtag = () => {
window.dataLayer = window.dataLayer || [];
function gtag(){dataLayer.push(arguments);}
gtag('js', new Date());
gtag('config', 'G-6H9C8TWXZ8');
}
(() => {
if (!localStorage.getItem("acceptedCookieAlert")) {
const boxElem = document.createElement("div");
boxElem.classList.add("cookie-alert");
const containerElem = document.createElement("div");
containerElem.classList.add("cookie-alert__container");
const textElem = document.createElement("p");
textElem.innerHTML = `This page uses <a href="https://analytics.google.com/">
Google Analytics</a> to collect statistics.`;
containerElem.appendChild(textElem);
const declineBtn = Object.assign(document.createElement("button"),
{
innerText: "Deny",
className: "farama-btn cookie-alert__button",
id: "cookie-alert__decline",
}
);
declineBtn.addEventListener("click", () => {
localStorage.setItem("acceptedCookieAlert", false);
boxElem.remove();
});
const acceptBtn = Object.assign(document.createElement("button"),
{
innerText: "Allow",
className: "farama-btn cookie-alert__button",
id: "cookie-alert__accept",
}
);
acceptBtn.addEventListener("click", () => {
localStorage.setItem("acceptedCookieAlert", true);
boxElem.remove();
enableGtag();
});
containerElem.appendChild(declineBtn);
containerElem.appendChild(acceptBtn);
boxElem.appendChild(containerElem);
document.body.appendChild(boxElem);
} else if (localStorage.getItem("acceptedCookieAlert") === "true") {
enableGtag();
}
})()
</script>
<script src="../../_static/documentation_options.js?v=25d39d6f"></script>
<script src="../../_static/doctools.js?v=9a2dae69"></script>
<script src="../../_static/sphinx_highlight.js?v=dc90522c"></script>
<script src="../../_static/scripts/furo.js?v=7660844c"></script>
<script>
const createProjectsList = (projects, displayImages) => {
const ulElem = Object.assign(document.createElement('ul'),
{
className:'farama-header-menu-list',
}
)
for (let project of projects) {
const liElem = document.createElement("li");
const aElem = Object.assign(document.createElement("a"),
{
href: project.link
}
);
liElem.appendChild(aElem);
if (displayImages) {
const imgElem = Object.assign(document.createElement("img"),
{
src: project.image ? imagesBasepath + project.image : imagesBasepath + "/farama_black.svg",
alt: `${project.name} logo`,
className: "farama-black-logo-invert"
}
);
aElem.appendChild(imgElem);
}
aElem.appendChild(document.createTextNode(project.name));
ulElem.appendChild(liElem);
}
return ulElem;
}
// Create menu with Farama projects by using the API at farama.org/api/projects.json
const createCORSRequest = (method, url) => {
let xhr = new XMLHttpRequest();
xhr.responseType = 'json';
if ("withCredentials" in xhr) {
xhr.open(method, url, true);
} else if (typeof XDomainRequest != "undefined") {
// IE8 & IE9
xhr = new XDomainRequest();
xhr.open(method, url);
} else {
// CORS not supported.
xhr = null;
}
return xhr;
};
const url = 'https://farama.org/api/projects.json';
const imagesBasepath = "https://farama.org/assets/images"
const method = 'GET';
let xhr = createCORSRequest(method, url);
xhr.onload = () => {
const jsonResponse = xhr.response;
const sections = {
"Core Projects": [],
"Mature Projects": {
"Documentation": [],
"Repositories": [],
},
"Incubating Projects": {
"Documentation": [],
"Repositories": [],
},
"Foundation": [
{
name: "About",
link: "https://farama.org/about"
},
{
name: "Standards",
link: "https://farama.org/project_standards",
},
{
name: "Donate",
link: "https://farama.org/donations"
}
]
}
// Categorize projects
Object.keys(jsonResponse).forEach(key => {
projectJson = jsonResponse[key];
if (projectJson.website !== null) {
projectJson.link = projectJson.website;
} else {
projectJson.link = projectJson.github;
}
if (projectJson.type === "core") {
sections["Core Projects"].push(projectJson)
} else if (projectJson.type == "mature") {
if (projectJson.website !== null) {
sections["Mature Projects"]["Documentation"].push(projectJson)
} else {
sections["Mature Projects"]["Repositories"].push(projectJson)
}
} else {
if (projectJson.website !== null) {
sections["Incubating Projects"]["Documentation"].push(projectJson)
} else {
sections["Incubating Projects"]["Repositories"].push(projectJson)
}
}
})
const menuContainer = document.querySelector(".farama-header-menu__body");
Object.keys(sections).forEach((key, i) => {
const sectionElem = Object.assign(
document.createElement('div'), {
className:'farama-header-menu__section',
}
)
sectionElem.appendChild(Object.assign(document.createElement('span'),
{
className:'farama-header-menu__section-title' ,
innerText: key
}
))
// is not a list
if (sections[key].constructor !== Array) {
const subSections = sections[key];
const subSectionContainerElem = Object.assign(
document.createElement('div'), {
className:'farama-header-menu__subsections-container',
style: 'display: flex'
}
)
Object.keys(subSections).forEach((subKey, i) => {
const subSectionElem = Object.assign(
document.createElement('div'), {
className:'farama-header-menu__subsection',
}
)
subSectionElem.appendChild(Object.assign(document.createElement('span'),
{
className:'farama-header-menu__subsection-title' ,
innerText: subKey
}
))
const ulElem = createProjectsList(subSections[subKey], key !== 'Foundation');
subSectionElem.appendChild(ulElem);
subSectionContainerElem.appendChild(subSectionElem);
})
sectionElem.appendChild(subSectionContainerElem);
} else {
const projects = sections[key];
const ulElem = createProjectsList(projects, true);
sectionElem.appendChild(ulElem);
}
menuContainer.appendChild(sectionElem)
});
}
xhr.onerror = function() {
console.error("Unable to load projects");
};
xhr.send();
</script>
<script>
const versioningConfig = {
githubUser: 'Farama-Foundation',
githubRepo: 'Gymnasium',
};
fetch('/main/_static/versioning/versioning_menu.html').then(response => {
if (response.status === 200) {
response.text().then(text => {
const container = document.createElement("div");
container.innerHTML = text;
document.querySelector("body").appendChild(container);
// innerHtml doenst evaluate scripts, we need to add them dynamically
Array.from(container.querySelectorAll("script")).forEach(oldScript => {
const newScript = document.createElement("script");
Array.from(oldScript.attributes).forEach(attr => newScript.setAttribute(attr.name, attr.value));
newScript.appendChild(document.createTextNode(oldScript.innerHTML));
oldScript.parentNode.replaceChild(newScript, oldScript);
});
});
} else {
console.warn("Unable to load versioning menu", response);
}
});
</script>
</body>
</html>