new_contents: import os
  import unicodecsv
  
  from smappdragon.tools.tweet_parser import TweetParser
  from smappdragon.collection.base_collection import BaseCollection
  
  class CsvCollection(BaseCollection):
      '''
          method that tells us how to
          create the CsvCollection object
      '''
      def __init__(self, filepath):
          BaseCollection.__init__(self)
          self.filepath = filepath
          if not os.path.isfile(filepath):
              raise IOError(filepath, 'CsvCollection could not find your file, it\'s mispelled or doesn\'t exist.')
  
      '''
          method that creates a cursor
          and yields all tweets in a particular collection
      '''
      def get_iterator(self):
          count = 1
          tweet_parser = TweetParser()
          csv_handle = open(self.filepath, 'rb')
          for tweet in unicodecsv.DictReader(csv_handle):
              if self.limit < count and self.limit != 0:
                  csv_handle.close()
                  return
              elif tweet_parser.tweet_passes_filter(self.filter, tweet) \
              and tweet_parser.tweet_passes_custom_filter_list(self.custom_filters, tweet):
                  count += 1
                  yield tweet
          csv_handle.close()
  
subject: work on csv collection