[PyCon Davao 2026] So You Think You Know Python?

Python is a language full of delightful surprises, if you know where to look. This talk takes you on a guided tour of its most interesting quirks, from easter eggs buried in the standard library, to real-world examples of how the language's gotchas have tripped up even the most seasoned developers.

This talk goes through code, documentation, PEPs, mailing list threads, discussions in issue trackers, webcomics, and other sources to get the answers to the following questions (and more):

- Is midnight falsy?
- Why does `~True` equal -2?
- What is the hash of infinity?
- How many references to xkcd webcomics are in the standard library?
- Why can't raw strings end with an odd number of backslashes?

Transcript

1. So You Think You Know Python? Jordan Duabe Software Engineer - - PyCon Davao, 2026 10 17
2. whoami Jordan Duabe Software Engineer at Anaqua - – - : – - Images (cropped) from L to R Виктор В, CC BY SA 3.0 Pedro Szekely from Los Angeles, USA, CC BY SA 2.0 Nestek, CC BY SA 4.0 (all via Wikimedia Commons) First World Metal Problems meme via Know Your Meme – Photos by Jordan Duabe
3. Agenda • Quirks and easter eggs • Gotchas and real world examples ) ( • Quiz ?
4. Quirks & easter eggs
5. The Zen of Python
6. PEP 20 Long time Pythoneer Tim Peters succinctly channels the BDFL s guiding principles for Python s design into 20 aphorisms, only 19 of which have been written ’ ’ down.
7. PEP 20
8. Hello world!
9. Hello world!
10. Breakfast of champions
11. Frozen modules
12. Frozen modules
13. PEP 401 The BDFL, having shepherded Python development for 20 years, officially announces his retirement effective immediately. Following a unanimous vote, his replacement is named.
14. Not equals
15. Brace yourselves
16. NOT like this
17. To Infinity and NaN
18. 𝜋 thon
19. 𝜋 thon
20. 𝜋 minus
21. xkcd 936 Generate an XKCD-style passphrase: import secrets # On standard Linux systems, use a convenient dictionary file. # Other platforms may need to provide their own word-list. with open('/usr/share/dict/words') as f: words = [word.strip() for word in f] password = ' '.join(secrets.choice(words) for i in range(4))
22. xkcd 2200
23. xkcd 353 >>> import antigravity
24. xkcd 426 >>> from antigravity import geohash
25. Gotchas & real world examples
26. Without warning
30. is equal
32. toronto.onepeloton.com Source: What a Bug can Teach You about Python by Brad Dettmer
33. The Bug Source: What a Bug can Teach You about Python by Brad Dettmer
34. Buggy code in backend server 257 257 if appointment.time_slot_id is ts.id: time_slot_appointments.append(appointment) Source: What a Bug can Teach You about Python by Brad Dettmer
35. Source: What a Bug can Teach You about Python by Brad Dettmer
36. Quiz
37. Thank You Contact • 📧 me@jduabe.dev • infosec.exchange/@j4ckofalltrades • github.com/j4ckofalltrades Slides
38. Links and sources https://hub.docker.com/r/j4ckofalltrades/legacy-python https://mail.python.org/pipermail/python-list/1999 June/001951.html https://docs.python.org/3/library/secrets.html https://sethmlarson.dev/deprecations-via-warnings-dont-work-for-python-libraries https://docs.python.org/3/c-api/long.html#:~:text=CPython,object https://docs.google.com/presentation/d/1mDeGnYlkYEvIuAfEGTyTk-vUaYvALkdqfnuGIRqz0Hs - • • • • • •
39. Image credits ) ) • ) • - • - "Australia relief map" by Виктор В, CC BY SA 3.0 (creativecommons.org/licenses/by-sa/3.0 . Source: en.wikipedia.org/wiki/File:Australia_relief_map.jpg "Rottnest Island coastline near Parker Point 01" by Pedro Szekely, CC BY SA 2.0 (creativecommons.org/ licenses/by-sa/2.0 . Source: commons.wikimedia.org/wiki/File:Rottnest_Island_coastline_near_Parker_Point_01.jpg "Quokkas Closeup" by Nestek, CC BY SA 4.0 (creativecommons.org/licenses/by-sa/4.0 . Source: commons.wikimedia.org/wiki/File:Quokkas_Closeup.jpg "First World Metal Problems" meme, via Know Your Meme. Source: knowyourmeme.com/photos/426359-first-world-metal-problems - •