Python re to extract useful information from each line

[Kashif Rana]

On Thursday, April 30, 2015 at 12:42:18 AM UTC+4, Kashif Rana wrote:
> Hello Experts
> 
> I have below lines with some variations.
> 
> 1- set policy id 1000 from "Untrust" to "Trust" "Any" "1.1.1.1" "HTTP" nat dst ip 10.10.10.10 port 8000 permit log
> 
> 2- set policy id 5000 from "Trust" to "Untrust" "Any" "microsoft.com" "HTTP" nat src permit schedule "14August2014" log
> 
> 3- set policy id 7000 from "Trust" to "Untrust" "Users" "Any" "ANY" nat src dip-id 4 permit log
> 
> 4- set policy id 7000 from "Trust" to "Untrust" "servers" "Any" "ANY" deny
> 
> Please help me to write the regular expression to extract below information in parenthesis, if exist from each line. Please note that some items may exist or not like nat or log
> 
> set policy id (id) from (from) to (to) (source) (destination) (service) nat (src or dst) (dip-id 4) or (ip 10.10.10.10) port (dst-port) (action) schedule (schedule) (log)

I tried below re and its not working.

id\s(?P<p_id>.+?)(?:\sname\s(?P<p_name>.+?))?\sfrom\s(?P<p_from>.+?)\sto\s(?P<p_to>.+?)\s{2}(?P<p_src>[^\s]+?)\s(?P<p_dst>[^\s]+?)\s(?P<p_port>[^\s]+?)(?:\s(?P<p_nat_status>nat)\s(?P<p_nat_type>\w+)(\s?P<p_nat_src_ip>dip-id\s\d+)?(\sip\s(?P<p_nat_dst_ip>[\d\.]+)\sport(?P<dst_nat_port>\d+))?)?\s(?P<p_action>[^\s]+?)(?:\sschedule\s(?P<p_schedule>[^\s]+?))?(?P<p_log_status>\slog)?$

If I ignore the line 1. I made below re and its working and giving me all info.

pol_elements = re.compile('id\s(?P<p_id>.+?)(?:\sname\s(?P<p_name>.+?))?\sfrom\s(?P<p_from>.+?)\sto\s(?P<p_to>.+?)\s{2}(?P<p_src>[^\s]+?)\s(?P<p_dst>[^\s]+?)\s(?P<p_port>[^\s]+?)(?:(?P<p_nat_status>\snat)\s(?P<p_nat_type>[^\s]+?)(?P<p_nat_ip>\sdip-id\s[^\s]+?)?)?\s(?P<p_action>[^\s]+?)(?:\sschedule\s(?P<p_schedule>[^\s]+?))?(?P<p_log_status>\slog)?$'
)