There should be open data on who is standing in elections right? Well if there is I couldn't find it. Instead I downloaded the PDFs that listed candidates from Lambeth website. I used the the command line version of Tabula to extract the data. I then geocoded the data using MySociety's fantastic MapIt API. All the data and code is on github.
Check out the How local are party candidates for the Lambeth council elections blog post for more info.
jruby -S gem install tabula-extractor