A quick bit of code to link postcode with constituency. Got the idea on how to implement from http://data.gov.uk/forum/general-discussion/mp-postcode-csv-file
If you want to link postcode with constituency, just download the 2015.04.03.postcode_to_constituency_lookup.tsv.gz file and gunzip.
Next step for me, will be to link constituency with demographic data from http://democraticdashboard.com/data/census/.
p.s. sorry for all the hardcoded paths, if anyone shows an interest, i will tidy it up.