On Jun 11, 3:25 pm, bvdp <[EMAIL PROTECTED]> wrote: > Is there a simple/safe expression evaluator I can use in a python > program. I just want to pass along a string in the form "1 + 44 / 3" or > perhaps "1 + (-4.3*5)" and get a numeric result. > > I can do this with eval() but I really don't want to subject my users to > the problems with that method. > > In this use I don't need python to worry about complex numbers, > variables or anything else. Just do the math on a set of values. Would > eval() with some restricted list of permitted operators do the trick? > > I'm feeling too lazy to write/debug my own parser for this :) > > Thanks, Bob.
This example ships with pyparsing, and can be extended to support built-in functions: http://pyparsing.wikispaces.com/space/showimage/fourFn.py. -- Paul -- http://mail.python.org/mailman/listinfo/python-list
