/Doc/library/xml.sax.utils.rst

 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. Lรถwis <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 ``'&amp;'``, ``'&lt;'``, and ``'&gt;'`` 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.  ``'&amp'``, ``'&lt;'``, and ``'&gt;'``
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 &quot; 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:`ContentHandler` interface by writing SAX
63   events back into an XML document. In other words, using an :class:`XMLGenerator`
64   as the content handler will reproduce the original document being parsed. *out*
65   should be a file-like object which will default to *sys.stdout*. *encoding* is
66   the encoding of the output stream which defaults to ``'iso-8859-1'``.
67
68
69.. class:: XMLFilterBase(base)
70
71   This class is designed to sit between an :class:`XMLReader` and the client
72   application's event handlers.  By default, it does nothing but pass requests up
73   to the reader and events on to the handlers unmodified, but subclasses can
74   override specific methods to modify the event stream or the configuration
75   requests as they pass through.
76
77
78.. function:: prepare_input_source(source[, base])
79
80   This function takes an input source and an optional base URL and returns a fully
81   resolved :class:`InputSource` object ready for reading.  The input source can be
82   given as a string, a file-like object, or an :class:`InputSource` object;
83   parsers will use this function to implement the polymorphic *source* argument to
84   their :meth:`parse` method.
85