Python Decorators

A basic understanding of Python Decorators.

Transcript

1. Decorators What are they? How to explain them. Tuesday, June 19, 12
2. Tuesday, June 19, 12
3. Basic definition Decorator is a function that takes a function as a parameter and returns a function Tuesday, June 19, 12
4. Basic definition Decorator is a function that takes a function as a parameter and returns a function Is a function. Takes a function. Returns a function Tuesday, June 19, 12
5. func = func_hugger(func) Illustration Tuesday, June 19, 12
6. def in_bed(func): def f(): return ‘%s In bed.’ % func() return f Change output Tuesday, June 19, 12
7. def in_bed(func): def f(): if f.in_pool: return ‘%s In pool.’ % func() return ‘%s In bed.’ % func() f.in_pool = False return f Add attributes Tuesday, June 19, 12
8. def in_bed(func): def f(*args, **kwargs): if args or kwargs: raise Exception(‘wat?’) return ‘%s In bed.’ % func() return f Validate Tuesday, June 19, 12
9. Tuesday, June 19, 12
10. Basic definition Is a function. Takes a function. Returns a function Tuesday, June 19, 12
11. Syntactic Sugar Annotation Syntax Tuesday, June 19, 12
12. Syntactic Sugar Annotation Syntax @func Tuesday, June 19, 12
13. def luke_quote(): return “I’m Luke SkyWalker, I’m here to rescue you.” Decorate Tuesday, June 19, 12
14. def luke_quote(): return “I’m Luke SkyWalker, I’m here to rescue you.” Decorate @in_bed Tuesday, June 19, 12
15. def luke_quote(): return “I’m Luke SkyWalker, I’m here to rescue you.” Decorate @in_bed @no_inbreeding Tuesday, June 19, 12
16. def luke_quote(): return “I’m Luke SkyWalker, I’m here to rescue you.” Decorate @in_bed(with=”lightsaber”) @in_bed Tuesday, June 19, 12
17. Tuesday, June 19, 12
18. @eloy Tuesday, June 19, 12