title: In Python ETL code, how does one implement metadata?
body: <p>I have a Python ETL process that moves data from MySQL databases to a Vertica data warehouse.  </p>
  
  <p>The ETL code opens files exported from MySQL, aggregates and denormalizes the data using Pythons Pandas library, and writes new files that are later loaded into the Vertica data warehouse.  The code is simple and works fine.</p>
  
  <p>I happened to run into a presentation on building large scale enterprise ETL networks, and the presenter stressed the importance of including metadata into the process, being able to have metadata about the data set, and schema information.  But there were no specifics given.</p>
  
  <p>This makes me think my ETL process, without any such metadata concept, is too amateurish, and I would like to incorporate this schema metadata concept.  Generally how do I do that?</p>
  
  <p>The presentation: <a href="https://www.youtube.com/watch?v=1SQWzG3FIu4#t=2418" rel="nofollow">https://www.youtube.com/watch?v=1SQWzG3FIu4#t=2418</a> 
  @40:20</p>