Hello. I'm trying to "parse" some LaTeX code (LaTeX uses

Question

Hello. I'm trying to "parse" some LaTeX code (LaTeX uses

some special characters such as %, #, \, {, } and delimits inline math environments with $ … $). What I need is to escape all special chars that are not already escaped and are not inside $ … $.

For example, for the provided entry "#s{o}me\%thing $ \text{a} $", I need to return "\#s\{o\}me\%thing $ \text{a} $".

I'm using re.sub to do that, and this way I can ignore the escaped ones, but I don't know how to ignore $ … $ environments. My current code is:

re.sub(r'([^\\]?)((?:%|#|{|}|#|&))', r"\1\\\2", string)

Any suggestions??

Edit: I wrote this on Stack Overflow with more details.