EDI parsing

[Onno Ebbinge]

I'm writing an application (in Python) that is part of a bigger 
infrastructure for B2B messaging. One communication channel is an EDI 
interface to the B2B messaging system.

I need to parse a (subset) of the UN EDIFACT (aka EDI) standard 
(homepage: http://www.unece.org/trade/untdid/welcome.htm). After doing 
the initial reading of the standard it looks like it is quite hard to 
make a parser for this standard (and ‘constructor').

My questions:

1) Is there a python EDI module? I can't find any :(
2) Is there a (python) EDI to XML converter?
3) Is there anything that I can use to easily interface with EDI?
   (preferably in lib and DLL form)

If the above is not available or fails... 

[You have to know that I've never written a parser in Python before. 
 The last (big) parser I wrote was in C with a few years back the help 
 of lex and yacc if memory serves me right.]

What is the best approach to writing an EDI parser in Python?

Thanks for your input,

Onno