Evaluating mathematical expressions in Python

Question

I want to tokenize a given mathematical expression into a parse tree like this:

((3 + 4 - 1) * 5 + 6 * -7) / 2

                          \'/\'
                      


        

Answer 1

I don't know of a "pure python" way to do this, that is already implemented for you. However you should check out ANTLR (http://www.antlr.org/) it's an open source parser an lexer and it has an API for a number of languages, including python. Also this website has some great video tutorials that will show you how to do exactly what you are asking. It's a very useful tool to know how to use in general.