CherryPy

Slide notes: https://github.com/whiteinge/presentations/tree/master/upyug_2013-05-09_cherrypy

Video: http://www.youtube.com/watch?v=IvbvfUeN9Eo

Transcript

1. CherryPy Seth House <seth@eseth.com> Utah Python 2013-05-09 Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 1 / 28
2. A minimalist Python web framework Outline 1 A minimalist Python web framework 2 CherryPy basics 3 Building an app 4 Conclusion Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 2 / 28
3. A minimalist Python web framework Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 3 / 28
4. A minimalist Python web framework History Remi Delon Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 4 / 28
5. A minimalist Python web framework History Remi Delon 2002: CherryPy CherryPy class processed to be self-contained module (app & server) Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 4 / 28
6. A minimalist Python web framework History Remi Delon 2002: CherryPy CherryPy class processed to be self-contained module (app & server) 2004: CherryPy 2 Object publishing Filters Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 4 / 28
7. A minimalist Python web framework History Remi Delon 2002: CherryPy CherryPy class processed to be self-contained module (app & server) 2004: CherryPy 2 Object publishing Filters 2005: CherryPy 2.1 Shipped with Turbogears Scrutiny; performance; WSGI support Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 4 / 28
8. A minimalist Python web framework History Remi Delon 2002: CherryPy CherryPy class processed to be self-contained module (app & server) 2004: CherryPy 2 Object publishing Filters 2005: CherryPy 2.1 Shipped with Turbogears Scrutiny; performance; WSGI support 2006: CherryPy 3 Book Turbogears 2.x chose Pylons Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 4 / 28
9. A minimalist Python web framework History Remi Delon 2002: CherryPy CherryPy class processed to be self-contained module (app & server) 2004: CherryPy 2 Object publishing Filters 2005: CherryPy 2.1 Shipped with Turbogears Scrutiny; performance; WSGI support 2006: CherryPy 3 Book Turbogears 2.x chose Pylons 2011: CherryPy 3.2 Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 4 / 28
10. A minimalist Python web framework Why CherryPy 2005 2006 2007 2008 2009 2010 2011 2012 2013 0 100 200 Figure: https://www.ohloh.net/p/cherrypy Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 5 / 28
11. A minimalist Python web framework Goals Simplicity No deps Lightly opinionated Community driven Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 6 / 28
12. A minimalist Python web framework Features Small (~600k) Featureful Plain functions or objects Extremely extendible Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 7 / 28
13. CherryPy basics Outline 1 A minimalist Python web framework 2 CherryPy basics 3 Building an app 4 Conclusion Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 8 / 28
14. CherryPy basics Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 9 / 28
15. CherryPy basics Basics Application framework Webserver Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 10 / 28
16. CherryPy basics Framework Configuration via dictionaries Seven hook functions Called during request/response cycle Caching Encoding Sessions & cookies Authorization Uploads Static content Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 11 / 28
17. CherryPy basics Framework Configuration via dictionaries Seven hook functions Called during request/response cycle Caching Encoding Sessions & cookies Authorization Uploads Static content No ORM / no templating / no forms Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 11 / 28
18. CherryPy basics Server Pure Python (Python 2.3+) HTTP/1.1 compliant Thread pooled Fast (1-2 ms per request) SSL (!) Cheroot: Stand-alone version Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 12 / 28
19. CherryPy basics Hello world Application and server: hello.py import cherrypy class HelloWorld: def index(self): return "Hello world!" index.exposed = True cherrypy.quickstart(HelloWorld()) Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 13 / 28
20. CherryPy basics import cherrypy help(cherrypy) Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 14 / 28
21. Building an app Outline 1 A minimalist Python web framework 2 CherryPy basics 3 Building an app 4 Conclusion Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 15 / 28
22. Building an app Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 16 / 28
23. Building an app Dispatchers Determine handler (via app config and URI) Set cherrypy.request.handler Wraps handler Collect config in cherrypy.request.config Extremely open-ended Use a custom by setting request.dispatch http://docs.cherrypy.org/stable/refman/ _cpdispatch.html Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 17 / 28
24. Building an app Default dispatcher For example: http://localhost/ -> root.index http://localhost/onepage -> root.onepage http://localhost/some/page -> root.some.page Or possibly: http://localhost/blog/2005/01/17 -> root.blog(self, year, month, day) Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 18 / 28
25. Building an app Handlers Any callable Current handler is cherrypy.request.handler Replace on the fly Must have exposed=True attribute Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 19 / 28
26. Building an app Handlers Any callable Current handler is cherrypy.request.handler Replace on the fly Must have exposed=True attribute .index attribute will take precedence default callable as fallback Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 19 / 28
27. Building an app Handlers Any callable Current handler is cherrypy.request.handler Replace on the fly Must have exposed=True attribute .index attribute will take precedence default callable as fallback POST data available as kwargs: class MyHandler(object): def search(self, q, lang, page): # do something with ‘‘q‘‘ Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 19 / 28
28. Building an app Config Dictionaries (!) Python code (run-time) ConfigParser ini files Python code (execution-time) Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 20 / 28
29. Building an app Config Dictionaries (!) Python code (run-time) ConfigParser ini files Python code (execution-time) Configure Dispatcher (per URL) request / response object attributes Hooks Tools Logging Server options Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 20 / 28
30. Building an app Config Dictionaries (!) Python code (run-time) ConfigParser ini files Python code (execution-time) Configure Dispatcher (per URL) request / response object attributes Hooks Tools Logging Server options Global config Application config Handler config: class MyHandler(object): _cp_config = {} Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 20 / 28
31. Building an app Tools Behavior outside handlers Many builtin Register / enable in the config: [/images] tools.staticdir.on: True Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 21 / 28
32. Building an app Tools Behavior outside handlers Many builtin Register / enable in the config: [/images] tools.staticdir.on: True Some usable as handler Directly callable Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 21 / 28
33. Building an app Tools Behavior outside handlers Many builtin Register / enable in the config: [/images] tools.staticdir.on: True Some usable as handler Directly callable Usable as decorators: @tools.staticdir(dir=’static’) def images(): ... Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 21 / 28
34. Building an app Writing tools def mytool(): # something! cherrypy.tools.mytool = Tool(’on_some_hook’, mytool) Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 22 / 28
35. Building an app Hooks on_start_resource before_request_body before_handler before_finalize on_end_resource before_error_response after_error_response on_end_request Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 23 / 28
36. Conclusion Outline 1 A minimalist Python web framework 2 CherryPy basics 3 Building an app 4 Conclusion Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 24 / 28
37. Conclusion Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 25 / 28
38. Conclusion Good Crazy flexible Lots of documentation Small Fast No deps Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 26 / 28
39. Conclusion Bad Documentation is scattered / some holes CherryPy 2 vs. 3 vs. 3.2 Small community Flexibility style can be tough to organize Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 27 / 28
40. Conclusion Walkthrough of a real app Demo of REST interface to Salt Request Response Reading headers Writing headers Redirects Exceptions WSGI Server Writing tests Seth House <seth@eseth.com> (Utah Python) CherryPy 2013-05-09 28 / 28