1:mod:`xml.sax.saxutils` --- SAX Utilities 2========================================= 3 4.. module:: xml.sax.saxutils 5 :synopsis: Convenience functions and classes for use with SAX. 6 7.. moduleauthor:: Lars Marius Garshol <larsga@garshol.priv.no> 8.. sectionauthor:: Martin v. Löwis <martin@v.loewis.de> 9 10**Source code:** :source:`Lib/xml/sax/saxutils.py` 11 12-------------- 13 14The module :mod:`xml.sax.saxutils` contains a number of classes and functions 15that are commonly useful when creating SAX applications, either in direct use, 16or as base classes. 17 18 19.. function:: escape(data, entities={}) 20 21 Escape ``'&'``, ``'<'``, and ``'>'`` in a string of data. 22 23 You can escape other strings of data by passing a dictionary as the optional 24 *entities* parameter. The keys and values must all be strings; each key will be 25 replaced with its corresponding value. The characters ``'&'``, ``'<'`` and 26 ``'>'`` are always escaped, even if *entities* is provided. 27 28 29.. function:: unescape(data, entities={}) 30 31 Unescape ``'&'``, ``'<'``, and ``'>'`` in a string of data. 32 33 You can unescape other strings of data by passing a dictionary as the optional 34 *entities* parameter. The keys and values must all be strings; each key will be 35 replaced with its corresponding value. ``'&'``, ``'<'``, and ``'>'`` 36 are always unescaped, even if *entities* is provided. 37 38 39.. function:: quoteattr(data, entities={}) 40 41 Similar to :func:`escape`, but also prepares *data* to be used as an 42 attribute value. The return value is a quoted version of *data* with any 43 additional required replacements. :func:`quoteattr` will select a quote 44 character based on the content of *data*, attempting to avoid encoding any 45 quote characters in the string. If both single- and double-quote characters 46 are already in *data*, the double-quote characters will be encoded and *data* 47 will be wrapped in double-quotes. The resulting string can be used directly 48 as an attribute value:: 49 50 >>> print("<element attr=%s>" % quoteattr("ab ' cd \" ef")) 51 <element attr="ab ' cd " ef"> 52 53 This function is useful when generating attribute values for HTML or any SGML 54 using the reference concrete syntax. 55 56 57.. class:: XMLGenerator(out=None, encoding='iso-8859-1', short_empty_elements=False) 58 59 This class implements the :class:`~xml.sax.handler.ContentHandler` interface 60 by writing SAX 61 events back into an XML document. In other words, using an :class:`XMLGenerator` 62 as the content handler will reproduce the original document being parsed. *out* 63 should be a file-like object which will default to *sys.stdout*. *encoding* is 64 the encoding of the output stream which defaults to ``'iso-8859-1'``. 65 *short_empty_elements* controls the formatting of elements that contain no 66 content: if ``False`` (the default) they are emitted as a pair of start/end 67 tags, if set to ``True`` they are emitted as a single self-closed tag. 68 69 .. versionadded:: 3.2 70 The *short_empty_elements* parameter. 71 72 73.. class:: XMLFilterBase(base) 74 75 This class is designed to sit between an 76 :class:`~xml.sax.xmlreader.XMLReader` and the client 77 application's event handlers. By default, it does nothing but pass requests up 78 to the reader and events on to the handlers unmodified, but subclasses can 79 override specific methods to modify the event stream or the configuration 80 requests as they pass through. 81 82 83.. function:: prepare_input_source(source, base='') 84 85 This function takes an input source and an optional base URL and returns a 86 fully resolved :class:`~xml.sax.xmlreader.InputSource` object ready for 87 reading. The input source can be given as a string, a file-like object, or 88 an :class:`~xml.sax.xmlreader.InputSource` object; parsers will use this 89 function to implement the polymorphic *source* argument to their 90 :meth:`parse` method. 91 92