new_contents: import pandas as pd
  import numpy as np
  
  train_users = pd.read_csv('/home/david/projects/airbnb-kaggle/datasets/raw/train_users.csv')
  test_users = pd.read_csv('/home/david/projects/airbnb-kaggle/datasets/raw/test_users.csv')
  sessions = pd.read_csv('/home/david/projects/airbnb-kaggle/datasets/raw/sessions.csv')
  
  print sessions.columns
  
  sessions.replace('-unknown-', np.nan)
  for user in sessions['user_id'].unique():
      user_session = sessions.loc[sessions['user_id'] == user]
      # Session length
      print len(user_session)
  
      # Action repetitions
      user_session['action_type'].value_counts()
  
      print user_session['action_type']
  
subject: Add little script