old_contents: #!/usr/bin/env python
  
  #import hashlib
  import os
  
  def main():
      for root, dirs, files in os.walk("/mcfs/data/materialscommons"):
          for f in files:
              print f
  
  if __name__ == "__main__":
      main()
  
new_contents: #!/usr/bin/env python
  
  import hashlib
  import os
  import rethinkdb as r
  
  def main():
      conn = r.connect('localhost', 28015, db='materialscommons')
      for root, dirs, files in os.walk("/mcfs/data/materialscommons"):
          for f in files:
              path = os.path.join(root, f)
              with open(path) as fd:
                  data = fd.read()
                  hash = hashlib.md5(data).hexdigest()
              s = os.stat(path).st_size
              r.table('datafiles').get(f).update({'size':s, 'checksum':hash}).run(conn)
              print "%s:%s:%d" %(path, hash, s)
  
  if __name__ == "__main__":
      main()
  
subject: Update script to write results to the database.