Upgrade to Pro — share decks privately, control downloads, hide ads and more …

Exceptional Exceptions - EuroPython 2019

Mario Corchero
July 11, 2019
Programming
1
110

Exceptional Exceptions - EuroPython 2019

Mario Corchero

July 11, 2019
Tweet

More Decks by Mario Corchero

See All by Mario Corchero
Linux & Python
mariocj89
0
75
Exceptional Exceptions
mariocj89
2
120
unittest.Mock in detail
mariocj89
0
210
Mocks: Successfully isolating the snake
mariocj89
1
87
Effortless logging: A deep dive into Python logging module
mariocj89
0
740
PyLondinium18 - London python Meetup
mariocj89
0
60
It's time for datetime
mariocj89
0
70
Pythons in the tower of babel
mariocj89
0
94

Other Decks in Programming

See All in Programming
Jasprが凄い話
hyshu
0
180
生成AIで加速するテスト実装 - ロリポップ for Gamersの事例と 生成AIエディタの活用
kinosuke01
0
130
pylint custom ruleで始めるレビュー自動化
shogoujiie
0
160
Rubyと自由とAIと
yotii23
6
1.8k
新宿駅構内を三人称視点で探索してみる
satoshi7190
2
120
PHPのバージョンアップ時にも役立ったAST
matsuo_atsushi
0
230
Domain-Driven Design (Tutorial)
hschwentner
13
22k
5分で理解する SOLID 原則 #phpcon_nagoya
shogogg
1
390
Serverless Rust: Your Low-Risk Entry Point to Rust in Production (and the benefits are huge)
lmammino
1
160
Honoをフロントエンドで使う 3つのやり方
yusukebe
7
3.6k
コミュニティ駆動 AWS CDK ライブラリ「Open Constructs Library」 / community-cdk-library
gotok365
2
250
AWS Step Functions は CDK で書こう！
konokenj
4
700

Featured

See All Featured
CSS Pre-Processors: Stylus, Less & Sass
bermonpainter
356
29k
Why You Should Never Use an ORM
jnunemaker
PRO
55
9.2k
Writing Fast Ruby
sferik
628
61k
Distributed Sagas: A Protocol for Coordinating Microservices
caitiem20
330
21k
Cheating the UX When There Is Nothing More to Optimize - PixelPioneers
stephaniewalter
280
13k
Sharpening the Axe: The Primacy of Toolmaking
bcantrill
40
2k
How To Stay Up To Date on Web Technology
chriscoyier
790
250k
Git: the NoSQL Database
bkeepers
PRO
428
65k
How to Create Impact in a Changing Tech Landscape [PerfNow 2023]
tammyeverts
49
2.3k
Building Your Own Lightsaber
phodgson
104
6.2k
Unsuck your backbone
ammeep
669
57k
VelocityConf: Rendering Performance Case Studies
addyosmani
328
24k

Transcript

  1. © 2019 Bloomberg Finance L.P. All rights reserved. Exceptional Exceptions:

    How to properly raise, handle and create them EuroPython 2019 July 11, 2019 Mario Corchero @mariocj89

  2. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Let’s just raise an exception, right?

  3. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Let’s just raise an exception, right?

  4. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Let’s go step by step

  5. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. How to capture an exception

  6. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. What can go in the except?

  7. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. What can go in the except?

  8. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Using finally

  9. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Using else

  10. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Order of execution?

  11. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. What about returning in the middle?

  12. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Logging exceptions Use exc_info to include exception information

  13. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Logging exceptions

  14. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Logging exceptions Errors should never pass silently. Unless explicitly silenced.

  15. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Logging exceptions

  16. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Logging exceptions But... When I have...

  17. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Logging exceptions But... What if I know...

  18. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Logging exceptions

  19. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Logging exceptions

  20. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Logging exceptions

  21. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Logging exceptions

  22. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Scoping of the except See PEP 3110. In short: exception -> traceback -> stack frame -> exception

  23. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Raise it!

  24. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. The tricky, raise within except

  25. © 2018 Bloomberg Finance L.P. All rights reserved. The tricky,

    raise within except

  26. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Reraise

  27. © 2018 Bloomberg Finance L.P. All rights reserved. Reraise

  28. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Reraise

  29. © 2018 Bloomberg Finance L.P. All rights reserved. Reraise

  30. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Chaining exceptions

  31. © 2018 Bloomberg Finance L.P. All rights reserved. Chaining exceptions

  32. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Eliding previous exception

  33. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Eliding previous exception

  34. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. False friends: NotImplemented Passes without printing. 37,762 hits in GitHub as of July 2019.

  35. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Raise on a thread?

  36. © 2018 Bloomberg Finance L.P. All rights reserved. Raise on

    a thread?

  37. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. The exception hierarchy Check https://docs.python.org/3/library/exceptions.html

  38. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Exception attributes

  39. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Exception attributes

  40. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Exception attributes

  41. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Creating new classes

  42. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Creating new classes

  43. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Exception hierarchy

  44. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Multiple inheritance • Decimal: • Requests:

  45. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Can I use Error codes?

  46. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Conclusions

  47. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Extra content!

  48. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. New magic in 3.8

  49. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. New magic in 3.8

  50. © 2019 Bloomberg Finance L.P. All rights reserved. Cycles when

    reraising

  51. © 2019 Bloomberg Finance L.P. All rights reserved. Cycles when

    reraising

  52. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Returns in finally

  53. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Returns in finally

  54. © 2018 Bloomberg Finance L.P. All rights reserved. © 2019

    Bloomberg Finance L.P. All rights reserved. Returns in finally

  55. © 2019 Bloomberg Finance L.P. All rights reserved. Thank you!

    Questions?? Also, ask me about travelling to Extremadura!