A reworking of a lightning talk presentation first made by Allen Short at PyCon 2012.

1. The Ministry of Truth
Rules for Good Software Design

2. Principles of good software design are
PRINCIPLES OF GOOD OBJECT DESIGN

3. War
is Peace

4. Treat all inputs
AS ATTACKS

6. A good interface
IS NOT BROKEN BY BAD INPUT

7. throw {
name: ”Bad Input Error”,
message: ”Oh noes!”
}

8. Freedom
is Slavery

9. The more you constrain your code’s behaviour,
THE MORE FREEDOM YOU HAVE TO ACT

10. run();

11. “There is only one mode,
AND IT IS SECURE.”

12. Ignorance
is Strength

13. Only give objects access to the
THINGS THEY NEED TO DO THEIR JOBS

14. To write better objects…
• Leave your object in a consistent state
regardless of what your clients do.
• Prevent clients from accessing things they
aren't supposed to touch.
• Only give your objects access to the
resources they need to get the job done.

15. To write better programs…
• Leave your program in a consistent state
regardless of what your clients do.
• Prevent clients from accessing things they
aren't supposed to touch.
• Only give your programs access to the
resources they need to get the job done.

16. Thanks
This lightning talk was originally by Allen Short
and was presented at PyCon 2012