What are python modules that can be used to potentially write malicious code?

I am trying to make a website what allows users to run python code. I've got the code part and running it down but there a matter of security too. I know that the os module and the fs module can be used to alter the actual server and this is something that shouldn't be allowed. Other than these modules, what are other modules what I can filter out and print a message to the user telling them that these keywords should not be used?