Job Security (in Python) (Christopher Neugebauer)

Transcript

1. Hello Canadia!
2. Job Security (in Python) Christopher Neugebauer @chrisjrn http://chris.neugebauer.id.au
3. Hello!
4. Why do people code Python?
5. “Readability” -- Raymond Hettinger, PyCon US 2013
6. “Readability Counts” -- Tim Peters, “The Zen of Python” (import this)
7. PEP 0008 “Style Guide for Python Code”
9. Readability Sucks.
10. 1. People can comprehend your code.
11. 2. You can maintain your own code.
12. 3. Your code will be more readily reusable.
13. THIS IS ALL BAD.
14. How do I write unmaintainable code?
15. 1) Obvious variable names
16. 1) Obvious (to you) variable names
17. • Callables: Superheroes • Classes: Musical characters • Strings: Famous actors • Numbers: Movie characters
18. MerryPoppins.captain_america(matt_damon, james_bond)
19. Spiderman.spiderman(spiderman)
20. 2) Metaprogramming
21. class Collection(Magic): def get_spam(self): return self.spam def set_spam(self, default): self.spam = default
22. >>> c = Collection() >>> c.set_spam(“eggs”)
23. >>> c = Collection() >>> c.set_spam(“eggs”) Traceback (most recent call last): File "<stdin>", line 1, in <module> File "<stdin>", line 10, in __getattribute__ TypeError: instancemethod expected at least 2 arguments, got 0
24. Help on Collection in module __main__ object: class Collection(Magic) | Method resolution order: | Collection | Magic | __builtin__.object | | Methods defined here: | | get_spam(self) | | set_spam(self, default)
25. TRANSLATE = (("get","_bork_"), ("set","_bork_"), ("canhas" , "get"), ("ihasa" , "set")) class Magic(object): def __getattribute__(self, attribute): oa = attribute for (key,val) in TRANSLATE: attribute = attribute.replace(key, val) try: return object. __getattribute__(self,attribute) except AttributeError: return type(object. __getattribute__(self, oa))
26. c.ihasa_spam("foo") -> c.set_spam(“foo”) c.canhas_spam() -> c.get_spam()
27. 3) Monkey patching
28. “A batteries-included standard library” -- Raymond Hettinger, PyCon US 2013
29. Roll your own standard library
30. >>> import math >>> math.cos(0)
31. >>> import math >>> math.cos(0) 0.0
32. >>> import magic >>> import math >>> math.cos(0) 0.0
33. import math math.cos, math.sin = math.sin, math.cos
34. - End -
35. This talk was a joke.
36. Don’t do this.
37. The end. Christopher Neugebauer @chrisjrn http://chris.neugebauer.id.au