Various bugs reported in python

Error 1

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Could not build atari-py: Command '['cmake', '..']' returned non-zero exit status 1..
 (HINT: are you sure cmake is installed? You might also be missing a library. Atari-py requires: zlib [installable as 'apt-get install zlib1g-dev' on Ubuntu].)

I encountered this error when installing ray==1.0.0 on windows, everything was normal when installing ray, but an error was reported when installing ray[rllib]!

install atari-py,

pip install atari-py -i https://mirrors.aliyun.com/pypi/simple

Error:

Solution : Change the atari-py version to 0.2.9

pip install atari-py==0.2.9 -i https://mirrors.aliyun.com/pypi/simple

success!

Then install ray[rllib] successfully.

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Error 2

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AttributeError: module 'contextlib' has no attribute 'nullcontext'

This is because python3.6 does not support contxtlib. contxtlib supports python3.7 in gym0.21.0.

Solve to install gym==0.20.0

pip install gym==0.20.0