From bdf95c1adc511a10fe115942bdef7b9b5f97516d Mon Sep 17 00:00:00 2001
From: Justin Terry <justinkterry@gmail.com>
Date: Thu, 17 Dec 2020 14:55:52 -0500
Subject: [PATCH] Python 3.9 support (#2088)

* try changes in pr 1804

* fix classifiers

* typo
---
 .travis.yml                       | 3 ++-
 gym/wrappers/pixel_observation.py | 4 +++-
 setup.py                          | 1 +
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index b7f3d094047..f051ec59bda 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -8,11 +8,12 @@ env:
   - PY_VER=3.6.12
   - PY_VER=3.7.9
   - PY_VER=3.8.6
+  - PY_VER=3.9.0
 
 install: "" # so travis doesn't do pip install requirements.txt
 script:
   - docker build -f py.Dockerfile --build-arg MUJOCO_KEY=$MUJOCO_KEY --build-arg PYTHON_VER=$PY_VER -t gym-test .
-  - docker run gym-test 
+  - docker run gym-test
 
 deploy:
     provider: pypi
diff --git a/gym/wrappers/pixel_observation.py b/gym/wrappers/pixel_observation.py
index 31b6db67aac..b25211023cc 100644
--- a/gym/wrappers/pixel_observation.py
+++ b/gym/wrappers/pixel_observation.py
@@ -1,6 +1,7 @@
 """An observation wrapper that augments observations by pixel values."""
 
 import collections
+from collections.abc import MutableMapping
 import copy
 
 import numpy as np
@@ -8,6 +9,7 @@
 from gym import spaces
 from gym import ObservationWrapper
 
+
 STATE_KEY = 'state'
 
 
@@ -60,7 +62,7 @@ def __init__(self,
             self._observation_is_dict = False
             invalid_keys = set([STATE_KEY])
         elif isinstance(wrapped_observation_space,
-                        (spaces.Dict, collections.MutableMapping)):
+                        (spaces.Dict, MutableMapping)):
             self._observation_is_dict = True
             invalid_keys = set(wrapped_observation_space.spaces.keys())
         else:
diff --git a/setup.py b/setup.py
index 3041b6ce547..3f661828a6d 100644
--- a/setup.py
+++ b/setup.py
@@ -48,5 +48,6 @@
           'Programming Language :: Python :: 3.6',
           'Programming Language :: Python :: 3.7',
           'Programming Language :: Python :: 3.8',
+          'Programming Language :: Python :: 3.9',
       ],
 )