Debugging for the Masses...Visually

Audience

Developers who have learned Python, and know they need to learn “that debugger thing”, but have either bounced off each attempt or gotten stuck at the basics.

Objectives

Attendees will understand why debugging is badass and helpful, what are the major concepts, how they apply during regular development, and how a visual debugger puts a friendly face on all of this. Walking out, debugging will seem not-scary-at-all.

This tutorial uses the free and open source PyCharm Community Edition, but the visual concepts apply to other IDEs as well.

Outline

Intro

Orientation - Hello World in arcade, command line - Hello World in arcade, in PyCharm Run - Hello World in arcade, in PyCharm Debug (without optimization) - Hello World in arcade, in PyCharm Debug (with optimization) - Hello World in arcade, with an error, jump to line

First Steps - Debugging without a debugger: Struggle through a print-oriented debug cycle - Debug with pdb - Set breakpoint - View variable information (Enhanced Variable Explorer, hides stuff) - Ditto, without restarting - Various knobs in the debug window, e.g. restart - Inline debugging

Productive Debugging - Setting/unsetting the “stop on exception” support - Using the console/IPython/Evaluate Expression at a breakpoint - Conditional breakpoint - All flavors of stepping - Inline debugging - Hands-on

In Depth - Stack frames - Watches - Manage all breakpoints