Joining two or more data sets together is a common operation that GIS Analysts perform. This can be done with Python. Some perquisites for joining data include creating (making) feature layers or tables views from feature classes or tables. Also, creating (adding) one or more indexes on data columns is good practice for larger datasets.
This video shows the process to work with attribute indexes, create (add) a join between a feature layer and table view, use the joined data in a search cursor process, and then remove the join after it is no longer needed.