as presented at the NZPUG meeting in Auckland, December 2008 - http://nzpug.org/MeetingsAuckland/Dec2008

2. Implementations of common design patterns in Python

4. Python Language features

5. Design patterns

6. If you have a specific problem -

7. you know what to Google for!

8. What if you (think you) don't?

9. Better name for this series? Please tell me!

10. TODAY Confirming a need

12. Decorator

13. Generator

14. Iterator

15. Meta class

17. Set

18. Queue

19. Threading

20. Closure

21. ...

23. How to use it

24. When to use it

26. Still not the first language

27. Who are these people?

28. Veni, vidi, vici

29. “Reads like pseudocode” - why not have a deeper look, this seems too good to be true

31. names = [p.name for p in people if p.age>20]

32. Exception Handling: Easier to ask forgiveness than for permission

33. (famous “is string representing an integer?”)

34. “There's only one way to do it”

35. (in a python interpreter, “import this” for the Zen)

38. Importing: a) from mymodule import *

39. b) relative/absolute/site-packages

40. Too general 'try...except:”

41. Standard library all over the show (PEP8 (2001) under_score/CamelCase, xmlrpc client/server (were) effectively incompatible...)

42. What others can you think of?

44. Bow

45. Green light

46. Rambo is ready to roll – bring it on!

47. Ready to roll?

50. Existing codebase not using it, retrofitting a bi***

51. Production server running old Python (Remember “True = 1”?)

52. Core problems taken care of by library or framework (one result: Pythonic vs. Zopish)

53. “Too busy coding”!

56. Tips & Tricks Often you need one little piece of information, and no one is to blame it's not there. Some things just... need some help

57. Setting the Name of a Function If an outer function just returns an inner function (often a closure), the name of the returned function object is fixed, which can be confusing when the name is shown during introspection or debugging: >>> def make_adder(addend): … def adder(augend): return augend+addend … return adder … >>> plus100 = make_adder(100) >>> plus_23 = make_adder(23) >>> print plus100(1000), plus_23(1000) 1100 1023 >>> print plus100, plus_23 <function adder at 0x386530> <function adder at 0x3825f0>

58. Python 2.4+ You can solve the problem by setting the __name_ attribute of the inner function before returning it: def make_adder(addend): def adder(augend): return augend+addend adder._name__ = 'add_%s' % (addend, ) With this change the output becomes more useful: >>> print plus100, plus_23 <function add_100 at 0x386530> <function add_23 at 0x3825f0>

59. Python 2.3 Unfortunately, the __name__ attribute is read-only in this release. The same effect is achieved by constructing a new function object which differs from the other only in name: import new def make_adder(addend): def adder(augend): return augend+addend return new.function( adder.func_code, adder.func_globals, 'add_%s' % (addend,), adder.func_defaults, adder.func_closure )