Python refactoring with rope and traad

This is a short presentation on rope, a Python refactoring library, and traad, an HTTP server which exposes rope's functionality. Traad is aimed at simplifying rope integration with editors and IDEs, so this presentation looks at how that can be achieved.

Transcript

1. PYTHON REFACTORING WITH ROPE AND TRAAD Austin Bingham Sixty North AS 0
2. HELLO!
3. PYTHON IS EVERYWHERE!
4. WHAT IS ROPE?
5. A PYTHON LIBRARY FOR DOING PYTHON REFACTORINGS
6. ROPE HAS POWERFUL IDE- ORIENTED FEATURES Code completion Finding definitions and occurrences Organizing imports Looking up docstrings
7. ELEMENTS OF ROPE
8. PROJECT Represents the files and directories containing code that rope will manipulate. P r o j e c t is the root object in rope
9. CREATE A PROJECT f r o m r o p e . b a s e . p r o j e c t i m p o r t P r o j e c t p r o j e c t = P r o j e c t ( ' p r o j e c t _ d i r ' )
10. WALK PROJECT RESOURCES d e f g e t _ a l l _ r e s o u r c e s ( p r o j ) : t o d o = [ ' ' ] w h i l e t o d o : r e s _ p a t h = t o d o [ 0 ] t o d o = t o d o [ 1 : ] r e s = p r o j . g e t _ r e s o u r c e ( r e s _ p a t h ) y i e l d ( r e s . p a t h , r e s . i s _ f o l d e r ( ) ) i f r e s . i s _ f o l d e r ( ) : t o d o . e x t e n d ( ( c h i l d . p a t h f o r c h i l d i n r e s . g e t _ c h i l d r e n ( ) ) ) P r o j e c t . g e t _ r e s o u r c e ( p a t h ) finds a resource at a relative path R e s o u r c e . g e t _ c h i l d r e n ( ) returns an iterable over children
11. MANAGE PREFERENCES p r e f s is a dict-like container of settings and preferences. f o r p i n p r o j e c t . p r e f s . p r e f s : p r i n t ( p r o j e c t . p r e f s . g e t ( p ) ) p r e f s are stored in a file called . r o p e p r o j e c t / c o n f i g . p y at the project's root directory.
12. RESOURCES The files and directories in the project s e r v e r = p r o j e c t . g e t _ r e s o u r c e ( ' t r a a d / s e r v e r . p y ' ) p r i n t ( s e r v e r . n a m e , s e r v e r . p a t h , s e r v e r . i s _ f o l d e r ( ) ) c 1 = p r o j e c t . g e t _ r e s o u r c e ( ' ' ) . g e t _ c h i l d r e n ( ) [ 0 ] p r i n t ( c 1 . n a m e , c 1 . p a t h , c 1 . i s _ f o l d e r ( ) )
13. ANATOMY OF A REFACTORING
14. CREATE THE REFACTORING OBJECT f r o m r o p e . r e f a c t o r . r e n a m e i m p o r t R e n a m e r e n = R e n a m e ( p r o j e c t , p r o j e c t . g e t _ r e s o u r c e ( ' t r a a d / s t a t e . p y ' ) , o f f s e t = 4 2 ) This can fail if rope can't perform the refactoring The refactoring is only partially bound
15. CALCULATE ACTUAL CHANGES c h a n g e s = r e n . g e t _ c h a n g e s ( ' T a c o C o p t e r ' ) p r i n t ( c h a n g e s . d e s c r i p t i o n ) p r i n t ( c h a n g e s . g e t _ c h a n g e d _ r e s o u r c e s ( ) ) c h a n g e s represents a fully bound change
16. EXECUTE THE CHANGES p r o j e c t . d o ( c h a n g e s ) After this the changes are actually performed.
17. THE FULL PROCESS f r o m r o p e . b a s e . p r o j e c t i m p o r t P r o j e c t f r o m r o p e . r e f a c t o r . r e n a m e i m p o r t R e n a m e # C r e a t e t h e p r o j e c t p r o j = P r o j e c t ( ' . ' ) # C r e a t e t h e p a r t i a l l y - b o u n d r e f a c t o r i n g r e n = R e n a m e ( p r o j e c t , p r o j e c t . g e t _ r e s o u r c e ( ' t r a a d / s t a t e . p y ' ) , o f f s e t = 4 2 ) # C a l c u l a t e t h e c h a n g e s f o r a f u l l y - s p e c i f i e d r e n a m i n g c h a n g e = r e n . g e t _ c h a n g e s ( ' T a c o C o p t e r ' ) # P e r f o r m t h e c h a n g e s p r o j e c t . d o . c h a n g e s ( )
18. HISTORY
19. H I S T O R Y OBJECT P r o j e c t . h i s t o r y manages the history of changes that have been made. Also remembers what has been undone as well as change dependencies.
20. UNDOING CHANGES Undo the most recent changes p r o j e c t . h i s t o r y . u n d o ( ) Or select more distance changes to undo c h a n g e = p r o j e c t . h i s t o r y . u n d o _ l i s t [ 3 ] p r o j e c t . h i s t o r y . u n d o ( c h a n g e ) This will undo all dependent changes.
21. REDOING CHANGES You can redo changes that you've previously undone. c h a n g e = p r o j e c t . h i s t o r y . r e d o _ l i s t [ - 2 ] p r o j e c t . h i s t o r y . r e d o ( c h a n g e )
22. MULTI-PROJECT REFACTORING
23. THE MULTI-PROJECT REFACTORING CLASS First create a M u l t i P r o j e c t R e f a c t o r i n g instance. f r o m r o p e . r e f a c t o r i m p o r t m u l t i p r o j e c t m p r = m u l t i p r o j e c t . M u l t i P r o j e c t R e f a c t o r i n g ( R e n a m e , # t y p e o f r e f a c t o r i n g t o p e r f o r m [ o t h e r _ p r o j e c t 1 , o t h e r _ p r o j e c t 2 , o t h e r _ p r o j e c t 3 ] ) Then call that with your main project and the refactoring initializer arguments r e f = m p r ( m a i n _ p r o j e c t , s o m e _ r e s o u r c e , o f f s e t = 1 3 3 7 )
24. CREATE AND PERFORM THE CHANGE # R e m e m b e r t h a t ` r e f ` i s a r e n a m i n g o p e r a t i o n c h a n g e s = r e f . g e t _ a l l _ c h a n g e s ( " E n t e r p r i s e P r o x y M a n a g e r I m p l e m e n t a t i o n F a c t o r y F a c t o r y " ) m u l t i p r o j e c t . p e r f o r m ( c h a n g e s )
25. NON-REFACTORING TOOLS
26. NOT INTENDED FOR "MANUAL" OPERATION
27. WHAT IS TRAAD? tråd - svært tynn snor av fibrer av silke, ull, el. f eks av metall
28. WHAT IS TRAAD? thread
29. TRAAD IS… An HTTP+JSON server for driving rope
30. TRAAD IS… Various clients for driving the server
31. WHY TRAAD?
32. SIMPLER INTEGRATION WITH EDITORS Every corner of the programming universe knows how to speak HTTP+JSON
33. HTTP IS (WAY) MORE THAN FAST ENOUGH FOR THIS WORK The volume of data is low, and the response time only needs to be good enough for humans
34. SUPPORT FOR MULTIPLE PYTHON VERSIONS The client has zero depenencies on the version of Python that traad is using
35. PROPER LEVEL OF ABSTRACTION The problem domain of traad is Python refactoring, not Python integration with other languages.
36. TRAAD ARCHITECTURE
37. Low-ceremony (sorta), powerful, and well-documented
38. PYKKA FOR MANAGING CONCURRENCY
39. OVERALL ARCHITECTURE
40. TASK STATE { 1 : { ' s t a t u s ' : ' p e n d i n g ' , ' d e s c r i p t i o n ' : ' R e n a m i n g F O O t o B A R ' , ' c h a n g e d _ r e s o u r c e s ' : [ . . . ] } , 2 : { ' s t a t u s ' : ' f a i l u r e ' } , 3 : { ' s t a t u s ' : ' s u c c e s s ' , ' c a l l t i p ' : ' u u i d 1 ( n o d e = N o n e , c l o c k _ s e q = N o n e ) ' } } Simple mapping of task-ids to dicts State is an actor and thus threadsafe. Multiple asynchronous tasks could be accessing it at any time.
41. ASYNCHRONOUS OPERATIONS
42. SYNCHRONOUS OPERATIONS
43. ASYCHRONOUS VS. SYNCHRONOUS Asynchronous Rename Extract Organize imports Synchronous Find definition Get history Calltip
44. EMACS The emacs lisp for renaming looks like this ; S t a r t s n e w t r a a d s e r v e r o n t h e s p e c i f i e d d i r e c t o r y ( t r a a d - o p e n " ~ / p r o j e c t s / r o i d _ r a g e " ) ; R e n a m e s w h a t e v e r i s a t h e p o i n t ( i . e . u n d e r t h e c u r s o r ) ( t r a a d - r e n a m e " R a g i n g R o i d " ) And the HTTP message looks like this P O S T / r e f a c t o r / r e n a m e H T T P / 1 . 1 U s e r - A g e n t : c u r l / 7 . 3 0 . 0 H o s t : 1 2 7 . 0 . 0 . 1 : 6 5 1 7 2 A c c e p t : * / * A c c e p t - E n c o d i n g : d e f l a t e , g z i p C o n t e n t - T y p e : a p p l i c a t i o n / j s o n C o n t e n t - L e n g t h : 1 0 4 { " n a m e " : " R a g i n g R o i d " , " p a t h " : " \ / U s e r s \ / s i x t y n o r t h \ / p r o j e c t s \ / r o i d _ r a g e \ / r o i d _ r a g e \ / r o i d . p y " , " o f f s e t " : 1 0 2 }
45. DEMOS
46. SIMPLE RENAMING
47. IMPORT CLEANUP
48. HISTORY
49. LINKS Rope - Traad - Pykka - Bottle - http://rope.sourceforge.net/ http://github.com/abingham/traad http://www.pykka.org/ http://bottlepy.org/ http://github.com/abingham/traad_rope_presentation