sre_parse.py - over-view or explanation needed

[korean_dave]

What does sre_parse.py (Secret Labs' Regular Expression Engine) do?

I see this referred to in some errors when i call the source()
function

(e.g. source(findFile("scripts","thisonehere.py")) )

The error then refers to name "ImportWarning" not defined?? (<--that
might be a proprietary warning, as I am running another app on top of
Python (not really relevant)).

I am curious how the sre_parse.py module gets involved when neither
the name or the file has any regular expression or special parse rules
in it....

So I guess the first step is understanding sre_parse.py itself. Can
someone help me on that?

Thanks.