title: *large* python dictionary with persistence storage for quick look-ups
body: <p>I have a 400 million lines of unique key-value info that I would like to be available for quick look ups in a script. I am wondering what would be a slick way of doing this. I did consider the following but not sure if there is a way to disk map the dictionary and without using a lot of memory except during dictionary creation. </p>
  
  <ol>
  <li>pickled dictionary object : not sure if this is an optimum solution for my problem</li>
  <li>NoSQL type dbases : ideally want something which has minimum dependency on third party stuff plus the key-value are simply numbers. If you feel this is still the best option, I would like to hear that too. May be it will convince me.</li>
  </ol>
  
  <p>Please let me know if anything is not clear.</p>
  
  <p>Thanks!
  -Abhi</p>