Parsing Email 'References' header.

[J. Cliff Dyer]

On Thu, 2008-05-08 at 14:53 +0200, Aspersieman wrote:
> Hi
> 
> I have a python script that parses email headers to extract information 
> from them. I need to get the _last_ messageid in the 'References' field 
> (http://cr.yp.to/immhf/thread.html) to create a threaded view of these 
> emails (these messageid's are stored in a database).
> 
> Now, I can easily access the 'References' field using the python 'email' 
> module, but I need a regular expression to get the last messageid in the 
> 'References' field.
> 
> Here's what I have so far:
> <code>
> rx_lastmesgid = re.compile(r"(<.+>$)")
> lastmesgid = "".join( filter( rx_lastmesgid.match, parentid ) ) # 
> parentid's value is 
> eg:"<1 at mail.gmail.com><2 at mail.gmail.com><3 at mail.gmail.com><4 at mail.gmail.com><5 at mail.gmail.com>"
> lastmesgid = "".join( filter( rx_lastmesgid.match, parentid ) )
> </code>
> 
> I need it to return "<5 at mail.gmail.com>"
> 
> Can anyone help?
> 
> Thanks
> 
> Nicol
> 

Forget regular expressions.  

py>>> lastmesgid = '<' + parentid.split('<')[-1]