user similarities map reduce job. this doesn't work!

userSimilarities-faulty.py

from mrjob.job import MRJob

# Put metrics here.

# add metrics to the below function.
def calculate_metrics(v1, v2):
  '''
  Calculates similarity metrics between two unfilled vectors.
  Returns [metric1, metric2, ...]
  '''
  return [some,metrics,go,here]


class MRUserSimilarities(MRJob):
  def __init__(self, *args, **kwargs):
    super(MRUserSimilarities, self).__init__(*args, **kwargs)
    self.postCounts = {}
    self.metrics = {}
      
  def map_identity(self, key, value):
    yield key, value

  def return_userIDs(self):
    for userID in self.postCounts:
      yield (userID, self.postCounts)
    
  def return_metric_userIDs(self):
    for userID in self.metrics:
      yield (userID, self.metrics[userID])
    
  def get_postcounts(self, key, line):
    '''
    Takes file input of the form userID\ttopicID\tpostCount
    Returns (userID, (topicID, postCount))
    '''
    splitLine = line.split()
    yield int(splitLine[0]), (int(splitLine[1]), int(splitLine[2]))
  def final_get_postcounts(self):
    for userID, postDict in self.postCounts.iteritems():
      yield userID, postDict
  
  def assemble_user_postcounts(self, userID, values):
    '''
    Takes userID as key and a list of (topicID, postCount) tuples as values
    Sets the global userID:topicID:postCount dict values.
    Returns userID, topicID:postCount dict.
    '''
    postDict = dict(values)
    if userID not in self.postCounts:
      self.postCounts[userID] = postDict
    else:
      for topicID in postDict:
        self.postCounts[userID][topicID] = postDict[topicID]
  
  def get_similarities(self, userID, postCounts):
    '''
    Takes userID and that userID's topicID:postCount dict
    Returns userID pairs with similarity metrics.
    '''
    userIDs = [key for key in postCounts if key > userID]
    for userID2 in userIDs:
      metrics = calculate_metrics(postCounts[userID], postCounts[userID2])
      if userID not in self.metrics:
        self.metrics[userID] = {userID2: metrics}
      else:
        self.metrics[userID][userID2] = metrics
    
  def output_similarities(self, userID, userMetrics):
    '''
    Takes a userID and list of similarities
    Returns outputtable values.
    '''
    for userID2 in userMetrics:
      yield userID, [userID2] + userMetrics[userID2]
    
  def steps(self):
    return [self.mr(mapper=self.get_postcounts,
                    mapper_final=self.final_get_postcounts,
                    reducer=self.assemble_user_postcounts,
                    reducer_final=self.return_userIDs),
            self.mr(mapper=self.get_similarities,
                    mapper_final=self.return_metric_userIDs,
                    reducer=self.output_similarities)]
  
if __name__ == '__main__':
  MRUserSimilarities.run()