pysandbox is a Python sandbox. By default, untrusted code executed in the sandbox cannot modify the environment (write a file, use print or import a module). But you can configure the sandbox to choose exactly which features are allowed or not, e.g. import sys module and read /etc/issue file. http://pypi.python.org/pypi/pysandbox https://github.com/haypo/pysandbox/ Main changes since pysandbox 1.0.3: - More modules and functions are allowed: math, random and time modules, and the compile() builtin function for example - Drop the timeout feature: it was not effective on CPU intensive functions implemented in C - (Read the ChangeLog to see all changes.) pysandbox has known limitations: - it is unable to limit memory or CPU - it does not protect against bugs (e.g. crash) or vulnerabilities in CPython - dict methods able to modify a dict (e.g. dict.update) are disabled to protect the sandbox namespace, but dict[key]=value is still accepted It is recommanded to run untrusted code in a subprocess to workaround these limitations. pysandbox doesn't provide an helper yet. pysandbox is used by an IRC bot (fschfsch) to evaluate a Python expression. The bot uses fork() and setrlimit() to limit memory and to implement a timeout. https://github.com/haypo/pysandbox/wiki/fschfsch -- The limitation on dict methods is required to deny the modification of the __builtins__ dictionary. I proposed the PEP 416 (frozendict) but Guido van Rossum is going to reject it. I don't see how to fix this limitation without modifying CPython. http://www.python.org/dev/peps/pep-0416/ Victor