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 .. note:: 29 30 This function should only be used to escape characters that 31 can't be used directly in XML. Do not use this function as a general 32 string translation function. 33 34.. function:: unescape(data, entities={}) 35 36 Unescape ``'&'``, ``'<'``, and ``'>'`` in a string of data. 37 38 You can unescape other strings of data by passing a dictionary as the optional 39 *entities* parameter. The keys and values must all be strings; each key will be 40 replaced with its corresponding value. ``'&'``, ``'<'``, and ``'>'`` 41 are always unescaped, even if *entities* is provided. 42 43 44.. function:: quoteattr(data, entities={}) 45 46 Similar to :func:`escape`, but also prepares *data* to be used as an 47 attribute value. The return value is a quoted version of *data* with any 48 additional required replacements. :func:`quoteattr` will select a quote 49 character based on the content of *data*, attempting to avoid encoding any 50 quote characters in the string. If both single- and double-quote characters 51 are already in *data*, the double-quote characters will be encoded and *data* 52 will be wrapped in double-quotes. The resulting string can be used directly 53 as an attribute value:: 54 55 >>> print("<element attr=%s>" % quoteattr("ab ' cd \" ef")) 56 <element attr="ab ' cd " ef"> 57 58 This function is useful when generating attribute values for HTML or any SGML 59 using the reference concrete syntax. 60 61 62.. class:: XMLGenerator(out=None, encoding='iso-8859-1', short_empty_elements=False) 63 64 This class implements the :class:`~xml.sax.handler.ContentHandler` interface 65 by writing SAX 66 events back into an XML document. In other words, using an :class:`XMLGenerator` 67 as the content handler will reproduce the original document being parsed. *out* 68 should be a file-like object which will default to *sys.stdout*. *encoding* is 69 the encoding of the output stream which defaults to ``'iso-8859-1'``. 70 *short_empty_elements* controls the formatting of elements that contain no 71 content: if ``False`` (the default) they are emitted as a pair of start/end 72 tags, if set to ``True`` they are emitted as a single self-closed tag. 73 74 .. versionchanged:: 3.2 75 Added the *short_empty_elements* parameter. 76 77 78.. class:: XMLFilterBase(base) 79 80 This class is designed to sit between an 81 :class:`~xml.sax.xmlreader.XMLReader` and the client 82 application's event handlers. By default, it does nothing but pass requests up 83 to the reader and events on to the handlers unmodified, but subclasses can 84 override specific methods to modify the event stream or the configuration 85 requests as they pass through. 86 87 88.. function:: prepare_input_source(source, base='') 89 90 This function takes an input source and an optional base URL and returns a 91 fully resolved :class:`~xml.sax.xmlreader.InputSource` object ready for 92 reading. The input source can be given as a string, a file-like object, or 93 an :class:`~xml.sax.xmlreader.InputSource` object; parsers will use this 94 function to implement the polymorphic *source* argument to their 95 :meth:`~xml.sax.xmlreader.XMLReader.parse` method. 96 97