Is there a re guru out there?

[Krzysiek Czarnowski]

I try to convert some LaTeX constructs to "plain" equivalents like \(,\) -->
$, \[,\] --> $$
and \frac{...}{...} --> {...\over ...}. The \frac bit appeared not to be
trivial since ... should be balanced with respect to { }. I found it hard to
specify with regular expressions.

Is it possible to achieve with re?
Best solution?

In practical situations even a partial solution would do. For example the
following
    no_group = r"[^\{\}]"
    grouped = r"\{%s*\}" % no_group
    balanced = r"((%s)|(%s))*" % (no_group, grouped)
matches any "one-level deep" balanced expression (roughly tested).
Is there a better way than just to proceed like this?

Krzysztof