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version::2.3.4 (Date(2007-03-17T15:00:00Z)) licence::BSD revised platforms::any platform that supports Python 2.3 Python versions::2.3 and above
Deployment Platforms
No requirement besides Python : Karrigell is provided with a web server and a Python database engine (["PyDbLite"]). It can also run behind Apache, LighTPD and Xitami
Suitability
Web programming
Demos included in the distribution include a Wiki server, Kwiki (a sort of Wiki, but with the wysiwyg editor FCKEditor), a forum, a calendar, an interface for script internationalization, and a portal with user login/logout, personalization and news editing
Version 2.3.2 introduced InstantSite, an application to manage MySQL or SQLite databases online
Development Interfaces
Servlet-style : the scripts, either pure Python or mixing HTML and Python, are executed in a namespace which provides all useful information, including HTTP headers, authentication data, etc. For instance, form fields are available as the QUERY dictionary, or with a variable with a leading underscore (the field myField is available as _myField, either a string or a list depending on the field type)
The namespace also provides custom exceptions to stop its execution, such as HTTP_REDIRECTION (see the on-line documentation)
A function Include(script_or_file, **args) allows the inclusion of an html file or of a file inside a script. If script B is included inside script A, it is executed in script A's namespace ; additional **args can be added to this namespace
Environment Access
Standard Python mechanisms : environment data is available in the namespace where scripts are executed
Session, Identification and Authentication
Provided through functions available in scripts
Session() returns a session object, to which attributes can be set (arbitrary Python objects : user login, database connexion and cursor, etc.)
Basic HTTP authentication is available with Authentication(testFunction[,realm,errorMessage]) where testFunction is a user-defined function taking no argument, which returns true if the authentication test succeeds (depending on the values of AUTH_USER and AUTH_PASSWORD) and false otherwise
Persistence Support
Karrigell is provided with the pure-Python ["PyDbLite"] database engine
It can be linked to all databases for which there is a Python API (SQLite, MySQL, PostGres, etc)
Presentation Support
- Python scripts, where the "print" statement is used to send output to the client
- "Karrigell services" : Python scripts where functions are mapped to URLs (allows to build a whole site with just one script)
"Python Inside HTML" (PIH) which looks like PHP, ASP, etc : HTML code with Python code inserted inside <% and %>, with shortcuts for variables : <%= myVar %> and for translated strings which use the gettext mechanism (for which Karrigell provides a simple interface) : <%_ "string to translate" %>
- "HTML Inside Python" which are Python scripts, except that the lines beginning with a string are sent to standard output as if there were a "print" statement before
- plain CGI scripts, running much faster than usual because the interpreter is not loaded for each request
InTheirOwnWords
Karrigell aims at simplicity for web developers :
- no separate web server
no separate database (["PyDbLite"] is included), although users can link to any base they like provided there is a Python API for it
- a namespace for Python scripts in which developers will find all useful data and functions for the most ordinary tasks
- a way to nest pages and scripts with the Include() function
The inspirations were EasyPHP, a package which provides Apache, PHP, mySql and PHPmyAdmin all in one, and saves the pain of installing each of them and make them all work together ; the wittily named Poor Man's Zope (PMZ) which showed how easy it was to make Python servlets (unfortunately unmaintained) ; and the pleasure I have programming things in Python
Performance and stability have been very much improved since the first versions. Karrigell can now be safely used in production environments
Comments
Hosting
[http://www.webfaction.com WebFaction] supports Karrigell