CherryPy

CherryPy

Developer(s)	CherryPy team
Stable release	3.2.0 / February 25, 2011; 8 months ago (2011-02-25)
Written in	Python
Operating system	Cross-platform
Type	Web application framework
License	BSD License
Website	homepage mailing list

CherryPy is an object-oriented web application framework using the Python programming language. It is designed for rapid development of web applications by wrapping the HTTP protocol but stays at a low level and does not offer much more than what is defined in RFC 2616.

CherryPy can be a web server itself or one can launch it via any WSGI compatible environment (including Apache 2). It does not deal with tasks such as templating for output rendering, backend access, authentication protocols. The framework is extensible with filters, simple interfaces made of seven functions. These are called at defined points in the request/response processing.

Pythonic interface

One of the goals of the project founder, Remi Delon, was to make CherryPy as pythonic as possible. This allows the developer to use the framework as any regular Python module and to forget (from a technical point of view) that the application is for the web.

For instance, the common Hello World program with CherryPy 3 would look like:

import cherrypy
 
class HelloWorld(object):
    def index(self):
        return "Hello World!"
    index.exposed = True
 
cherrypy.quickstart(HelloWorld())

Features [1]

• A fast, HTTP/1.1-compliant, WSGI thread-pooled webserver. Typically, CherryPy itself takes ^[1][2] only 1-2 ms per page.
• Support for any other WSGI-enabled web server or adapter, including Apache, IIS, lighttpd, mod_python, FastCGI, SCGI, and mod_wsgi.
• A native mod_python adapter.
• Easy to run multiple HTTP servers (e.g. on multiple ports) at once ^[3].
• A flexible plugin system ^[4]. CherryPy plugins hook into events within the server process — into server startup, server shutdown, server exiting, etc. — to run code that needs to be run when the server starts up or shuts down.
• Built-in tools for caching, encoding, sessions, authorization, static content, and many more. CherryPy tools hook into events within the request process. Whenever the CherryPy server receives a request, there is a specific set of steps it goes through to handle that request. Page handlers are only one step in the process. Tools also provide a very powerful syntax and configuration API for turning them on and off for a specific set of handlers.
• A powerful configuration system for developers and deployers alike ^[5][6][7]. CherryPy deployments are configurable on site, on application and on controller level, through Python dictionaries, configuration files, and open file objects.
• Swappable and customizable every component [2].
• A complete test suite ^[8]:
  • Lots of tests for both basic and advanced functionality.
  • Command-line options to control which tests are run, and the output they produce.
  • Debugging tools specifically for web page tests.
  • Many of the test suite components are reusable by applications.
• Built-in profiling since v2.1 ^[9], coverage ^[10] and testing support.

Applications

• Websites running atop CherryPy.
• People who use CherryPy.
• Products based on/inspired by CherryPy.

Some open source connection

Free software portal

CherryPy doesn’t force you to use a specific object-relational mapper, template language or JavaScript library. You are free to use any kind of technology you want.

Can be used with CherryPy

• Routes ^[11] — a Python re-implementation of the Ruby on Rails's routes system for mapping URLs to controllers/actions and generating URLs.

Object-relational mappers

• SQLAlchemy — a database backend and ORM for Python applications. TurboGears 2.x uses CherryPy as server and SQLAlchemy as its default ORM ^[12].
• SQLObject — a popular ORM for providing an object interface to your database. Supports a number of common database backends: included in the distribution are MySQL, PostgreSQL, SQLite, Sybase SQL Server, MaxDB, Microsoft SQL Server and Firebird. TurboGears 1.x uses CherryPy as server and SQLObject as ORM ^[13].
• Storm — the ORM from Canonical Ltd. (makers of Ubuntu).
• Dejavu — a public domain, thread-safe ORM for Python applications.

Templating languages

• Mako — a template library written in Python, usable with a simple CherryPy tool ^[14].
• Cheetah — an open source template engine and code generation tool, written in Python.
• CherryTemplate — a templating language for CherryPy.
• Genshi ^[15][16] — a powerful XML templating language.
• Jinja — a general purpose templating language. CherryPy has a tool for using Jinja templates ^[17].
• Kid — a simple template language for XML based vocabularies written in Python. TurboGears 1.x uses CherryPy as server and Kid as frontend ^[18].

CherryPy wiki helps ^[19] choosing a templating language.

JavaScript libraries

• Sarissa[3] — a cross-browser library for Ajax.
• jQuery — a lightweight library that emphasizes interaction between JavaScript and HTML.
• Pyjamas — a Python to JavaScript compiler and a web widget set.

CherryPy is a component of

• TurboGears — CherryPy is a main component of TurboGears 1.x.

Further reading

• CherryPy Essentials: Rapid Python Web Application Development, First Edition (March 2007), ISBN 978-1-904811-84-8

References

• CherryPy on Freshmeat
• CherryPy on Ohloh

External links

• CherryPy website
• Documentation
• Feeds about CherryPy

Notes

1. ^ CherryPy v3 WSGI server benchmark results
2. ^ How fast is CherryPy?
3. ^ How to setup multiple HTTP servers with CherryPy
4. ^ Custom engine plugins with CherryPy
5. ^ Configuration system of CherryPy
6. ^ Configuration API of CherryPy
7. ^ Short summary of configuration options
8. ^ How to test CherryPy itself
9. ^ Profiler module of CherryPy
10. ^ How to collect and the analyse coverage data of application code with CherryPy
11. ^ A simple dispatcher tool for CherryPy that uses Routes
12. ^ TurboGears 2.x uses CherryPy as server and SQLAlchemy as its default ORM
13. ^ TurboGears 1.x uses CherryPy as server and SQLObject as ORM
14. ^ A simple CherryPy tool for Mako templating
15. ^ "CherryPy – Genshi". http://genshi.edgewall.org/wiki/CherryPy. Retrieved 2009-09-26. 
16. ^ "Genshi - CherryPy Tools - Trac". http://tools.cherrypy.org/wiki/Genshi. Retrieved 2009-09-26. 
17. ^ A basic CherryPy Tool for using Jinja templates
18. ^ TurboGears 1.x uses CherryPy as server and Kid as frontend
19. ^ CherryPy wiki about choosing a templating language