In order to download and install OpenAI Gym, you can use any of the following options:
$ git clone https://github.com/openai/gym
$ cd gym
$ sudo pip install -e . # minimal install
This will do the minimum install. You can later run the following to do a full install:
$ sudo pip install -e .[all]
You can also fetch Gym as a package for different Python versions as follows:
For Python 2.7, you can use the following options:
$ sudo pip install gym # minimal install
$ sudo pip install gym[all] # full install
$ sudo pip install gym[atari] #for Atari specific environment installation
For Python 3.5, you can use the following options:
$ sudo pip3 install gym # minimal install...
$ sudo pip3 install gym[all] # full install
$ sudo pip install gym[atari] #for Atari specific environment installation