If pudb is not installed in your machine, do :

sudo yum install python-pudb.noarch

or

sudo yum install python3-pudb.noarch

Add in your python file

import pudb;pu.db

to break at this line and start the debugger. Alternatively, start your scripts with the pudb or pudb3 command instead of python or python3

You can find a tutorial here : http://heather.cs.ucdavis.edu/~matloff/pudb.html