title: ARIMA prediction model saved into file and used later on for forecasting
body: <p>I want to save the ARIMA model object I created for future use - how to do it in the most efficient form? Right now, I create the model, say arima_mod, and use <code>arima_mod.forecast()</code>. How can I save this model as text and revoke it later on? I am pretty sure that it can be done with <code>pickle</code> but I don't understand how to call it properly for this case...</p>
  
  <p>Thanks!</p>