code: def recruit_participants(self, n=1):
          
          auto_recruit = os.environ['auto_recruit'] == 'true'
  
          if auto_recruit:
  
              print "Starting Wallace's recruit_participants."
  
              hit_id = str(
                  Participant.query.
                  with_entities(Participant.hitid).first().hitid)
  
              print "hit_id is {}.".format(hit_id)
  
              is_sandbox = self.config.getboolean(
                  'Shell Parameters', 'launch_in_sandbox_mode')
  
              if is_sandbox:
                  host = 'mechanicalturk.sandbox.amazonaws.com'
              else:
                  host = 'mechanicalturk.amazonaws.com'
  
              mturkparams = dict(
                  aws_access_key_id=self.aws_access_key_id,
                  aws_secret_access_key=self.aws_secret_access_key,
                  host=host)
  
              self.mtc = MTurkConnection(**mturkparams)
  
              self.mtc.extend_hit(
                  hit_id,
                  assignments_increment=int(n or 0))
  
              expiration_increment = self.config.get('HIT Configuration',
                                                     'duration')
  
              self.mtc.extend_hit(
                  hit_id,
                  expiration_increment=int(
                      float(expiration_increment or 0) * 3600))
          else:
              print(">>>> auto_recruit set to {}: recruitment suppressed"
                    .format(auto_recruit))
docs: Recruit n participants.