>>> import ast
>>> mylist = ast.literal_eval("['foo', ['cat', ['ant', 'bee'], 'dog'], 'bar', 'baz']")
>>> mylist
['foo', ['cat', ['ant', 'bee'], 'dog'], 'bar', 'baz']
ast.literal_eval:
Safely evaluate an expression node or
a string containing a Python
expression. The string or node
provided may only consist of the
following Python literal structures:
strings, numbers, tuples, lists,
dicts, booleans, and None.
This can be used for safely evaluating
strings containing Python expressions
from untrusted sources without the
need to parse the values oneself.