I highly recommened pudb, which is a full-screen, console-based visual debugger for Python. The user-interface is nicely designed for python developers.
Here is an example debugging a simple python script:
Introduction to the PuDB Python Debugging Tool
Also, another great tutorial is from Jordi Gutiérrez Hermoso.
Montreal, QC, September 14, 2015 - Jordi Gutiérrez Hermoso presents PuDB, a full-screen, console-based visual debugger for Python.
An interesting comment from the speaker:
Everyone should use a debugger
But If pdb is the only debugger you've every seen, I won't blame you not using a debugger
because the debugger is ugly, not because the source code is ugly
To install pudb on Debian/Ubuntu, you can use apt-get to install the package