1 2:mod:`xml.sax.saxutils` --- SAX Utilities 3========================================= 4 5.. module:: xml.sax.saxutils 6 :synopsis: Convenience functions and classes for use with SAX. 7.. moduleauthor:: Lars Marius Garshol <larsga@garshol.priv.no> 8.. sectionauthor:: Martin v. Löwis <martin@v.loewis.de> 9 10 11.. versionadded:: 2.0 12 13The module :mod:`xml.sax.saxutils` contains a number of classes and functions 14that are commonly useful when creating SAX applications, either in direct use, 15or as base classes. 16 17 18.. function:: escape(data[, entities]) 19 20 Escape ``'&'``, ``'<'``, and ``'>'`` in a string of data. 21 22 You can escape other strings of data by passing a dictionary as the optional 23 *entities* parameter. The keys and values must all be strings; each key will be 24 replaced with its corresponding value. The characters ``'&'``, ``'<'`` and 25 ``'>'`` are always escaped, even if *entities* is provided. 26 27 28.. function:: unescape(data[, entities]) 29 30 Unescape ``'&'``, ``'<'``, and ``'>'`` in a string of data. 31 32 You can unescape other strings of data by passing a dictionary as the optional 33 *entities* parameter. The keys and values must all be strings; each key will be 34 replaced with its corresponding value. ``'&'``, ``'<'``, and ``'>'`` 35 are always unescaped, even if *entities* is provided. 36 37 .. versionadded:: 2.3 38 39 40.. function:: quoteattr(data[, entities]) 41 42 Similar to :func:`escape`, but also prepares *data* to be used as an 43 attribute value. The return value is a quoted version of *data* with any 44 additional required replacements. :func:`quoteattr` will select a quote 45 character based on the content of *data*, attempting to avoid encoding any 46 quote characters in the string. If both single- and double-quote characters 47 are already in *data*, the double-quote characters will be encoded and *data* 48 will be wrapped in double-quotes. The resulting string can be used directly 49 as an attribute value:: 50 51 >>> print "<element attr=%s>" % quoteattr("ab ' cd \" ef") 52 <element attr="ab ' cd " ef"> 53 54 This function is useful when generating attribute values for HTML or any SGML 55 using the reference concrete syntax. 56 57 .. versionadded:: 2.2 58 59 60.. class:: XMLGenerator([out[, encoding]]) 61 62 This class implements the :class:`~xml.sax.handler.ContentHandler` interface 63 by writing SAX 64 events back into an XML document. In other words, using an :class:`XMLGenerator` 65 as the content handler will reproduce the original document being parsed. *out* 66 should be a file-like object which will default to *sys.stdout*. *encoding* is 67 the encoding of the output stream which defaults to ``'iso-8859-1'``. 68 69 70.. class:: XMLFilterBase(base) 71 72 This class is designed to sit between an 73 :class:`~xml.sax.xmlreader.XMLReader` and the client 74 application's event handlers. By default, it does nothing but pass requests up 75 to the reader and events on to the handlers unmodified, but subclasses can 76 override specific methods to modify the event stream or the configuration 77 requests as they pass through. 78 79 80.. function:: prepare_input_source(source[, base]) 81 82 This function takes an input source and an optional base URL and returns a 83 fully resolved :class:`~xml.sax.xmlreader.InputSource` object ready for 84 reading. The input source can be given as a string, a file-like object, or 85 an :class:`~xml.sax.xmlreader.InputSource` object; parsers will use this 86 function to implement the polymorphic *source* argument to their 87 :meth:`parse` method. 88 89