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(python2.1-lib.info)xml.sax

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Support for SAX2 parsers
========================

Package containing SAX2 base classes and convenience functions.  This
module was written by Lars Marius Garshol <larsga@garshol.priv.no>.
This manual section was written by Fred L. Drake, Jr. <fdrake@acm.org>.
This manual section was written by Martin v. L"owis
<loewis@informatik.hu-berlin.de>.
_Added in Python version 2.0_

The `xml.sax' package provides a number of modules which implement the
Simple API for XML (SAX) interface for Python.  The package itself
provides the SAX exceptions and the convenience functions which will be
most used by users of the SAX API.

The convenience functions are:

`make_parser([parser_list])'
     Create and return a SAX `XMLReader' object.  The first parser
     found will be used.  If PARSER_LIST is provided, it must be a
     sequence of strings which name modules that have a function named
     `create_parser()'.  Modules listed in PARSER_LIST will be used
     before modules in the default list of parsers.

`parse(filename_or_stream, handler[, error_handler])'
     Create a SAX parser and use it to parse a document.  The document,
     passed in as FILENAME_OR_STREAM, can be a filename or a file
     object.  The HANDLER parameter needs to be a SAX `ContentHandler'
     instance.  If ERROR_HANDLER is given, it must be a SAX
     `ErrorHandler' instance; if omitted, `SAXParseException' will be
     raised on all errors.  There is no return value; all work must be
     done by the HANDLER passed in.

`parseString(string, handler[, error_handler])'
     Similar to `parse()', but parses from a buffer STRING received as
     a parameter.

A typical SAX application uses three kinds of objects: readers,
handlers and input sources.  "Reader" in this context is another term
for parser, i.e. some piece of code that reads the bytes or characters
from the input source, and produces a sequence of events.  The events
then get distributed to the handler objects, i.e. the reader invokes a
method on the handler.  A SAX application must therefore obtain a
reader object, create or open the input sources, create the handlers,
and connect these objects all together.  As the final step of
preparation, the reader is called to parse the input.  During parsing,
methods on the handler objects are called based on structural and
syntactic events from the input data.

For these objects, only the interfaces are relevant; they are normally
not instantiated by the application itself.  Since Python does not have
an explicit notion of interface, they are formally introduced as
classes, but applications may use implementations which do not inherit
from the provided classes.  The `InputSource', `Locator',
`AttributesImpl', `AttributesNSImpl', and `XMLReader' interfaces are
defined in the module `xml.sax.xmlreader'.  The handler interfaces are
defined in `xml.sax.handler'.  For convenience, `InputSource' (which is
often instantiated directly) and the handler classes are also available
from `xml.sax'.  These interfaces are described below.

In addition to these classes, `xml.sax' provides the following
exception classes.

`SAXException(msg[, exception])'
     Encapsulate an XML error or warning.  This class can contain basic
     error or warning information from either the XML parser or the
     application: it can be subclassed to provide additional
     functionality or to add localization.  Note that although the
     handlers defined in the `ErrorHandler' interface receive instances
     of this exception, it is not required to actually raise the
     exception -- it is also useful as a container for information.

     When instantiated, MSG should be a human-readable description of
     the error.  The optional EXCEPTION parameter, if given, should be
     `None' or an exception that was caught by the parsing code and is
     being passed along as information.

     This is the base class for the other SAX exception classes.

`SAXParseException(msg, exception, locator)'
     Subclass of `SAXException' raised on parse errors.  Instances of
     this class are passed to the methods of the SAX `ErrorHandler'
     interface to provide information about the parse error.  This
     class supports the SAX `Locator' interface as well as the
     `SAXException' interface.

`SAXNotRecognizedException(msg[, exception])'
     Subclass of `SAXException' raised when a SAX `XMLReader' is
     confronted with an unrecognized feature or property.  SAX
     applications and extensions may use this class for similar
     purposes.

`SAXNotSupportedException(msg[, exception])'
     Subclass of `SAXException' raised when a SAX `XMLReader' is asked
     to enable a feature that is not supported, or to set a property to
     a value that the implementation does not support.  SAX
     applications and extensions may use this class for similar
     purposes.

See also:
     `SAX: The Simple API for XML'{This site is the focal point for the
     definition of the SAX API.  It provides a Java implementation and
     online documentation.  Links to implementations and historical
     information are also available.}

SAXException Objects