getting values from an "exec" statement

[Toby Donaldson]

Hi all,

I'm designing an educational application that will run Python code and
check the output against a pre-define answer. I want to use the "exec"
statement to run the code, but I don't know how to get output from it.

For instance, exec works like this:

>>> code = """
for i in xrange(1, 5):
print i
"""
>>> exec code
1
2
3
4

I want to store the values output by the print statement in a list. Is
there anyway to re-direct the output of the exec statement?

Also, it would be nice if exec had a timeout that automatically
haulted code that ran for too long. Is there a standard trick for
this? I expect I would have to run it in its own thread and kill the
thread when it takes too long (which reminds me I don't know anything
about Python threads!).

Toby