Core Python Programming (2nd Edition)

14.6. Restricted Execution

At one time in Python's history, there was the concept of restricted execution using the rexec and Bastion modules. The first allowed you to modify the built-in objects that were made available to code executing in a sandbox. The second served as an attribute filter and wrapper around your classes. However, due to a well-known vulnerability and the difficulty in fixing the security hole, these modules are no longer used or accessible; their documentation serves only those maintaining old code using these modules.