[OpenSPARC-T2-SAM] / sam-t2 / devtools / v8plus / html / python / lib / module-xml.dom.minidom.html

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<link rel="STYLESHEET" href="lib.css" type='text/css' />
<link rel="SHORTCUT ICON" href="../icons/pyfav.png" type="image/png" />
<link rel='start' href='../index.html' title='Python Documentation Index' />
<link rel="first" href="lib.html" title='Python Library Reference' />
<link rel='contents' href='contents.html' title="Contents" />
<link rel='index' href='genindex.html' title='Index' />
<link rel='last' href='about.html' title='About this document...' />
<link rel='help' href='about.html' title='About this document...' />
<link rel="next" href="module-xml.dom.pulldom.html" />
<link rel="prev" href="module-xml.dom.html" />
<link rel="parent" href="markup.html" />
<link rel="next" href="dom-objects.html" />
<meta name='aesop' content='information' />
<title>13.7 xml.dom.minidom -- Lightweight DOM implementation</title>
</head>
<body>
<DIV CLASS="navigation">
<div id='top-navigation-panel' xml:id='top-navigation-panel'>
<table align="center" width="100%" cellpadding="0" cellspacing="2">
<tr>
<td class='online-navigation'><a rel="prev" title="13.6.3.2 Accessor Methods"
  href="dom-accessor-methods.html"><img src='../icons/previous.png'
  border='0' height='32'  alt='Previous Page' width='32' /></A></td>
<td class='online-navigation'><a rel="parent" title="13. Structured Markup Processing"
  href="markup.html"><img src='../icons/up.png'
  border='0' height='32'  alt='Up One Level' width='32' /></A></td>
<td class='online-navigation'><a rel="next" title="13.7.1 DOM Objects"
  href="dom-objects.html"><img src='../icons/next.png'
  border='0' height='32'  alt='Next Page' width='32' /></A></td>
<td align="center" width="100%">Python Library Reference</td>
<td class='online-navigation'><a rel="contents" title="Table of Contents"
  href="contents.html"><img src='../icons/contents.png'
  border='0' height='32'  alt='Contents' width='32' /></A></td>
<td class='online-navigation'><a href="modindex.html" title="Module Index"><img src='../icons/modules.png'
  border='0' height='32'  alt='Module Index' width='32' /></a></td>
<td class='online-navigation'><a rel="index" title="Index"
  href="genindex.html"><img src='../icons/index.png'
  border='0' height='32'  alt='Index' width='32' /></A></td>
</tr></table>
<div class='online-navigation'>
<b class="navlabel">Previous:</b>
<a class="sectref" rel="prev" href="dom-accessor-methods.html">13.6.3.2 Accessor Methods</A>
<b class="navlabel">Up:</b>
<a class="sectref" rel="parent" href="markup.html">13. Structured Markup Processing</A>
<b class="navlabel">Next:</b>
<a class="sectref" rel="next" href="dom-objects.html">13.7.1 DOM Objects</A>
</div>
<hr /></div>
</DIV>
<!--End of Navigation Panel-->

<H1><A NAME="SECTION0015700000000000000000">
13.7 <tt class="module">xml.dom.minidom</tt> --
         Lightweight DOM implementation</A>
</H1>

<P>
<A NAME="module-xml.dom.minidom"></A>

<P>

<span class="versionnote">New in version 2.0.</span>

<P>
<tt class="module">xml.dom.minidom</tt> is a light-weight implementation of the
Document Object Model interface.  It is intended to be
simpler than the full DOM and also significantly smaller.

<P>
DOM applications typically start by parsing some XML into a DOM.  With
<tt class="module">xml.dom.minidom</tt>, this is done through the parse functions:

<P>
<div class="verbatim"><pre>
from xml.dom.minidom import parse, parseString

dom1 = parse('c:\\temp\\mydata.xml') # parse an XML file by name

datasource = open('c:\\temp\\mydata.xml')
dom2 = parse(datasource)   # parse an open file

dom3 = parseString('&lt;myxml&gt;Some data&lt;empty/&gt; some more data&lt;/myxml&gt;')
</pre></div>

<P>
The <tt class="function">parse()</tt> function can take either a filename or an open
file object.

<P>
<dl><dt><table cellpadding="0" cellspacing="0"><tr valign="baseline">
  <td><nobr><b><tt id='l2h-4445' xml:id='l2h-4445' class="function">parse</tt></b>(</nobr></td>
  <td><var>filename_or_file, parser</var>)</td></tr></table></dt>
<dd>
  Return a <tt class="class">Document</tt> from the given input. <var>filename_or_file</var>
  may be either a file name, or a file-like object. <var>parser</var>, if
  given, must be a SAX2 parser object. This function will change the
  document handler of the parser and activate namespace support; other
  parser configuration (like setting an entity resolver) must have been
  done in advance.
</dl>

<P>
If you have XML in a string, you can use the
<tt class="function">parseString()</tt> function instead:

<P>
<dl><dt><table cellpadding="0" cellspacing="0"><tr valign="baseline">
  <td><nobr><b><tt id='l2h-4446' xml:id='l2h-4446' class="function">parseString</tt></b>(</nobr></td>
  <td><var>string</var><big>[</big><var>, parser</var><big>]</big><var></var>)</td></tr></table></dt>
<dd>
  Return a <tt class="class">Document</tt> that represents the <var>string</var>. This
  method creates a <tt class="class">StringIO</tt> object for the string and passes
  that on to <tt class="function">parse</tt>.
</dl>

<P>
Both functions return a <tt class="class">Document</tt> object representing the
content of the document.

<P>
What the <tt class="function">parse()</tt> and <tt class="function">parseString()</tt> functions do
is connect an XML parser with a ``DOM builder'' that can accept parse
events from any SAX parser and convert them into a DOM tree.  The name
of the functions are perhaps misleading, but are easy to grasp when
learning the interfaces.  The parsing of the document will be
completed before these functions return; it's simply that these
functions do not provide a parser implementation themselves.

<P>
You can also create a <tt class="class">Document</tt> by calling a method on a ``DOM
Implementation'' object.  You can get this object either by calling
the <tt class="function">getDOMImplementation()</tt> function in the
<tt class="module"><a href="module-xml.dom.html">xml.dom</a></tt> package or the <tt class="module">xml.dom.minidom</tt> module.
Using the implementation from the <tt class="module">xml.dom.minidom</tt> module will
always return a <tt class="class">Document</tt> instance from the minidom
implementation, while the version from <tt class="module"><a href="module-xml.dom.html">xml.dom</a></tt> may provide
an alternate implementation (this is likely if you have the
<a class="ulink" href="http://pyxml.sourceforge.net/"
  >PyXML package</a> installed).  Once
you have a <tt class="class">Document</tt>, you can add child nodes to it to populate
the DOM:

<P>
<div class="verbatim"><pre>
from xml.dom.minidom import getDOMImplementation

impl = getDOMImplementation()

newdoc = impl.createDocument(None, "some_tag", None)
top_element = newdoc.documentElement
text = newdoc.createTextNode('Some textual content.')
top_element.appendChild(text)
</pre></div>

<P>
Once you have a DOM document object, you can access the parts of your
XML document through its properties and methods.  These properties are
defined in the DOM specification.  The main property of the document
object is the <tt class="member">documentElement</tt> property.  It gives you the
main element in the XML document: the one that holds all others.  Here
is an example program:

<P>
<div class="verbatim"><pre>
dom3 = parseString("&lt;myxml&gt;Some data&lt;/myxml&gt;")
assert dom3.documentElement.tagName == "myxml"
</pre></div>

<P>
When you are finished with a DOM, you should clean it up.  This is
necessary because some versions of Python do not support garbage
collection of objects that refer to each other in a cycle.  Until this
restriction is removed from all versions of Python, it is safest to
write your code as if cycles would not be cleaned up.

<P>
The way to clean up a DOM is to call its <tt class="method">unlink()</tt> method:

<P>
<div class="verbatim"><pre>
dom1.unlink()
dom2.unlink()
dom3.unlink()
</pre></div>

<P>
<tt class="method">unlink()</tt> is a <tt class="module">xml.dom.minidom</tt>-specific extension to
the DOM API.  After calling <tt class="method">unlink()</tt> on a node, the node and
its descendants are essentially useless.

<P>
<div class="seealso">
  <p class="heading">See Also:</p>

  <dl compact="compact" class="seetitle">
    <dt><em class="citetitle"><a href="http://www.w3.org/TR/REC-DOM-Level-1/"
        >Document Object
            Model (DOM) Level 1 Specification</a></em></dt>
    <dd>The W3C recommendation for the
            DOM supported by <tt class="module">xml.dom.minidom</tt>.</dd>
  </dl>
</div>

<P>

<p><br /></p><hr class='online-navigation' />
<div class='online-navigation'>
<!--Table of Child-Links-->
<A NAME="CHILD_LINKS"><STRONG>Subsections</STRONG></a>

<UL CLASS="ChildLinks">
<LI><A href="dom-objects.html">13.7.1 DOM Objects</a>
<LI><A href="dom-example.html">13.7.2 DOM Example</a>
<LI><A href="minidom-and-dom.html">13.7.3 minidom and the DOM standard</a>
</ul>
<!--End of Table of Child-Links-->
</div>

<DIV CLASS="navigation">
<div class='online-navigation'>
<p></p><hr />
<table align="center" width="100%" cellpadding="0" cellspacing="2">
<tr>
<td class='online-navigation'><a rel="prev" title="13.6.3.2 Accessor Methods"
  href="dom-accessor-methods.html"><img src='../icons/previous.png'
  border='0' height='32'  alt='Previous Page' width='32' /></A></td>
<td class='online-navigation'><a rel="parent" title="13. Structured Markup Processing"
  href="markup.html"><img src='../icons/up.png'
  border='0' height='32'  alt='Up One Level' width='32' /></A></td>
<td class='online-navigation'><a rel="next" title="13.7.1 DOM Objects"
  href="dom-objects.html"><img src='../icons/next.png'
  border='0' height='32'  alt='Next Page' width='32' /></A></td>
<td align="center" width="100%">Python Library Reference</td>
<td class='online-navigation'><a rel="contents" title="Table of Contents"
  href="contents.html"><img src='../icons/contents.png'
  border='0' height='32'  alt='Contents' width='32' /></A></td>
<td class='online-navigation'><a href="modindex.html" title="Module Index"><img src='../icons/modules.png'
  border='0' height='32'  alt='Module Index' width='32' /></a></td>
<td class='online-navigation'><a rel="index" title="Index"
  href="genindex.html"><img src='../icons/index.png'
  border='0' height='32'  alt='Index' width='32' /></A></td>
</tr></table>
<div class='online-navigation'>
<b class="navlabel">Previous:</b>
<a class="sectref" rel="prev" href="dom-accessor-methods.html">13.6.3.2 Accessor Methods</A>
<b class="navlabel">Up:</b>
<a class="sectref" rel="parent" href="markup.html">13. Structured Markup Processing</A>
<b class="navlabel">Next:</b>
<a class="sectref" rel="next" href="dom-objects.html">13.7.1 DOM Objects</A>
</div>
</div>
<hr />
<span class="release-info">Release 2.4.2, documentation updated on 28 September 2005.</span>
</DIV>
<!--End of Navigation Panel-->
<ADDRESS>
See <i><a href="about.html">About this document...</a></i> for information on suggesting changes.
</ADDRESS>
</BODY>
</HTML>
Commit	Line	Data
920dae64 AT	1	<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
	2	<html>
	3	<head>
	4	<link rel="STYLESHEET" href="lib.css" type='text/css' />
	5	<link rel="SHORTCUT ICON" href="../icons/pyfav.png" type="image/png" />
	6	<link rel='start' href='../index.html' title='Python Documentation Index' />
	7	<link rel="first" href="lib.html" title='Python Library Reference' />
	8	<link rel='contents' href='contents.html' title="Contents" />
	9	<link rel='index' href='genindex.html' title='Index' />
	10	<link rel='last' href='about.html' title='About this document...' />
	11	<link rel='help' href='about.html' title='About this document...' />
	12	<link rel="next" href="module-xml.dom.pulldom.html" />
	13	<link rel="prev" href="module-xml.dom.html" />
	14	<link rel="parent" href="markup.html" />
	15	<link rel="next" href="dom-objects.html" />
	16	<meta name='aesop' content='information' />
	17	<title>13.7 xml.dom.minidom -- Lightweight DOM implementation</title>
	18	</head>
	19	<body>
	20	<DIV CLASS="navigation">
	21	<div id='top-navigation-panel' xml:id='top-navigation-panel'>
	22	<table align="center" width="100%" cellpadding="0" cellspacing="2">
	23	<tr>
	24	<td class='online-navigation'><a rel="prev" title="13.6.3.2 Accessor Methods"
	25	href="dom-accessor-methods.html"><img src='../icons/previous.png'
	26	border='0' height='32' alt='Previous Page' width='32' /></A></td>
	27	<td class='online-navigation'><a rel="parent" title="13. Structured Markup Processing"
	28	href="markup.html"><img src='../icons/up.png'
	29	border='0' height='32' alt='Up One Level' width='32' /></A></td>
	30	<td class='online-navigation'><a rel="next" title="13.7.1 DOM Objects"
	31	href="dom-objects.html"><img src='../icons/next.png'
	32	border='0' height='32' alt='Next Page' width='32' /></A></td>
	33	<td align="center" width="100%">Python Library Reference</td>
	34	<td class='online-navigation'><a rel="contents" title="Table of Contents"
	35	href="contents.html"><img src='../icons/contents.png'
	36	border='0' height='32' alt='Contents' width='32' /></A></td>
	37	<td class='online-navigation'><a href="modindex.html" title="Module Index"><img src='../icons/modules.png'
	38	border='0' height='32' alt='Module Index' width='32' /></a></td>
	39	<td class='online-navigation'><a rel="index" title="Index"
	40	href="genindex.html"><img src='../icons/index.png'
	41	border='0' height='32' alt='Index' width='32' /></A></td>
	42	</tr></table>
	43	<div class='online-navigation'>
	44	<b class="navlabel">Previous:</b>
	45	<a class="sectref" rel="prev" href="dom-accessor-methods.html">13.6.3.2 Accessor Methods</A>
	46	<b class="navlabel">Up:</b>
	47	<a class="sectref" rel="parent" href="markup.html">13. Structured Markup Processing</A>
	48	<b class="navlabel">Next:</b>
	49	<a class="sectref" rel="next" href="dom-objects.html">13.7.1 DOM Objects</A>
	50	</div>
	51	<hr /></div>
	52	</DIV>
	53	<!--End of Navigation Panel-->
	54
	55	<H1><A NAME="SECTION0015700000000000000000">
	56	13.7 <tt class="module">xml.dom.minidom</tt> --
	57	Lightweight DOM implementation</A>
	58	</H1>
	59
	60	<P>
	61	<A NAME="module-xml.dom.minidom"></A>
	62
	63	<P>
	64
65	<span class="versionnote">New in version 2.0.</span>
66
67	<P>
68	<tt class="module">xml.dom.minidom</tt> is a light-weight implementation of the
69	Document Object Model interface. It is intended to be
70	simpler than the full DOM and also significantly smaller.
71
72	<P>
73	DOM applications typically start by parsing some XML into a DOM. With
74	<tt class="module">xml.dom.minidom</tt>, this is done through the parse functions:
75
76	<P>
77	<div class="verbatim"><pre>
78	from xml.dom.minidom import parse, parseString
79
80	dom1 = parse('c:\\temp\\mydata.xml') # parse an XML file by name
81
82	datasource = open('c:\\temp\\mydata.xml')
83	dom2 = parse(datasource) # parse an open file
84
85	dom3 = parseString('<myxml>Some data<empty/> some more data</myxml>')
86	</pre></div>
87
88	<P>
89	The <tt class="function">parse()</tt> function can take either a filename or an open
90	file object.
91
92	<P>
93	<dl><dt><table cellpadding="0" cellspacing="0"><tr valign="baseline">
94	<td><nobr><b><tt id='l2h-4445' xml:id='l2h-4445' class="function">parse</tt></b>(</nobr></td>
95	<td><var>filename_or_file, parser</var>)</td></tr></table></dt>
96	<dd>
97	Return a <tt class="class">Document</tt> from the given input. <var>filename_or_file</var>
98	may be either a file name, or a file-like object. <var>parser</var>, if
99	given, must be a SAX2 parser object. This function will change the
100	document handler of the parser and activate namespace support; other
101	parser configuration (like setting an entity resolver) must have been
102	done in advance.
103	</dl>
104
105	<P>
106	If you have XML in a string, you can use the
107	<tt class="function">parseString()</tt> function instead:
108
109	<P>
110	<dl><dt><table cellpadding="0" cellspacing="0"><tr valign="baseline">
111	<td><nobr><b><tt id='l2h-4446' xml:id='l2h-4446' class="function">parseString</tt></b>(</nobr></td>
112	<td><var>string</var><big>[</big><var>, parser</var><big>]</big><var></var>)</td></tr></table></dt>
113	<dd>
114	Return a <tt class="class">Document</tt> that represents the <var>string</var>. This
115	method creates a <tt class="class">StringIO</tt> object for the string and passes
116	that on to <tt class="function">parse</tt>.
117	</dl>
118
119	<P>
120	Both functions return a <tt class="class">Document</tt> object representing the
121	content of the document.
122
123	<P>
124	What the <tt class="function">parse()</tt> and <tt class="function">parseString()</tt> functions do
125	is connect an XML parser with a ``DOM builder'' that can accept parse
126	events from any SAX parser and convert them into a DOM tree. The name
127	of the functions are perhaps misleading, but are easy to grasp when
128	learning the interfaces. The parsing of the document will be
129	completed before these functions return; it's simply that these
130	functions do not provide a parser implementation themselves.
131
132	<P>
133	You can also create a <tt class="class">Document</tt> by calling a method on a ``DOM
134	Implementation'' object. You can get this object either by calling
135	the <tt class="function">getDOMImplementation()</tt> function in the
136	<tt class="module"><a href="module-xml.dom.html">xml.dom</a></tt> package or the <tt class="module">xml.dom.minidom</tt> module.
137	Using the implementation from the <tt class="module">xml.dom.minidom</tt> module will
138	always return a <tt class="class">Document</tt> instance from the minidom
139	implementation, while the version from <tt class="module"><a href="module-xml.dom.html">xml.dom</a></tt> may provide
140	an alternate implementation (this is likely if you have the
141	<a class="ulink" href="http://pyxml.sourceforge.net/"
142	>PyXML package</a> installed). Once
143	you have a <tt class="class">Document</tt>, you can add child nodes to it to populate
144	the DOM:
145
146	<P>
147	<div class="verbatim"><pre>
148	from xml.dom.minidom import getDOMImplementation
149
150	impl = getDOMImplementation()
151
152	newdoc = impl.createDocument(None, "some_tag", None)
153	top_element = newdoc.documentElement
154	text = newdoc.createTextNode('Some textual content.')
155	top_element.appendChild(text)
156	</pre></div>
157
158	<P>
159	Once you have a DOM document object, you can access the parts of your
160	XML document through its properties and methods. These properties are
161	defined in the DOM specification. The main property of the document
162	object is the <tt class="member">documentElement</tt> property. It gives you the
163	main element in the XML document: the one that holds all others. Here
164	is an example program:
165
166	<P>
167	<div class="verbatim"><pre>
168	dom3 = parseString("<myxml>Some data</myxml>")
169	assert dom3.documentElement.tagName == "myxml"
170	</pre></div>
171
172	<P>
173	When you are finished with a DOM, you should clean it up. This is
174	necessary because some versions of Python do not support garbage
175	collection of objects that refer to each other in a cycle. Until this
176	restriction is removed from all versions of Python, it is safest to
177	write your code as if cycles would not be cleaned up.
178
179	<P>
180	The way to clean up a DOM is to call its <tt class="method">unlink()</tt> method:
181
182	<P>
183	<div class="verbatim"><pre>
184	dom1.unlink()
185	dom2.unlink()
186	dom3.unlink()
187	</pre></div>
188
189	<P>
190	<tt class="method">unlink()</tt> is a <tt class="module">xml.dom.minidom</tt>-specific extension to
191	the DOM API. After calling <tt class="method">unlink()</tt> on a node, the node and
192	its descendants are essentially useless.
193
194	<P>
195	<div class="seealso">
196	<p class="heading">See Also:</p>
197
198	<dl compact="compact" class="seetitle">
199	<dt><em class="citetitle"><a href="http://www.w3.org/TR/REC-DOM-Level-1/"
200	>Document Object
201	Model (DOM) Level 1 Specification</a></em></dt>
202	<dd>The W3C recommendation for the
203	DOM supported by <tt class="module">xml.dom.minidom</tt>.</dd>
204	</dl>
205	</div>
206
207	<P>
208
209	<p><br /></p><hr class='online-navigation' />
210	<div class='online-navigation'>
211	<!--Table of Child-Links-->
212	<A NAME="CHILD_LINKS"><STRONG>Subsections</STRONG></a>
213
214	<UL CLASS="ChildLinks">
215	<LI><A href="dom-objects.html">13.7.1 DOM Objects</a>
216	<LI><A href="dom-example.html">13.7.2 DOM Example</a>
217	<LI><A href="minidom-and-dom.html">13.7.3 minidom and the DOM standard</a>
218	</ul>
219	<!--End of Table of Child-Links-->
220	</div>
221
222	<DIV CLASS="navigation">
223	<div class='online-navigation'>
224	<p></p><hr />
225	<table align="center" width="100%" cellpadding="0" cellspacing="2">
226	<tr>
227	<td class='online-navigation'><a rel="prev" title="13.6.3.2 Accessor Methods"
228	href="dom-accessor-methods.html"><img src='../icons/previous.png'
229	border='0' height='32' alt='Previous Page' width='32' /></A></td>
230	<td class='online-navigation'><a rel="parent" title="13. Structured Markup Processing"
231	href="markup.html"><img src='../icons/up.png'
232	border='0' height='32' alt='Up One Level' width='32' /></A></td>
233	<td class='online-navigation'><a rel="next" title="13.7.1 DOM Objects"
234	href="dom-objects.html"><img src='../icons/next.png'
235	border='0' height='32' alt='Next Page' width='32' /></A></td>
236	<td align="center" width="100%">Python Library Reference</td>
237	<td class='online-navigation'><a rel="contents" title="Table of Contents"
238	href="contents.html"><img src='../icons/contents.png'
239	border='0' height='32' alt='Contents' width='32' /></A></td>
240	<td class='online-navigation'><a href="modindex.html" title="Module Index"><img src='../icons/modules.png'
241	border='0' height='32' alt='Module Index' width='32' /></a></td>
242	<td class='online-navigation'><a rel="index" title="Index"
243	href="genindex.html"><img src='../icons/index.png'
244	border='0' height='32' alt='Index' width='32' /></A></td>
245	</tr></table>
246	<div class='online-navigation'>
247	<b class="navlabel">Previous:</b>
248	<a class="sectref" rel="prev" href="dom-accessor-methods.html">13.6.3.2 Accessor Methods</A>
249	<b class="navlabel">Up:</b>
250	<a class="sectref" rel="parent" href="markup.html">13. Structured Markup Processing</A>
251	<b class="navlabel">Next:</b>
252	<a class="sectref" rel="next" href="dom-objects.html">13.7.1 DOM Objects</A>
253	</div>
254	</div>
255	<hr />
256	<span class="release-info">Release 2.4.2, documentation updated on 28 September 2005.</span>
257	</DIV>
258	<!--End of Navigation Panel-->
259	<ADDRESS>
260	See <i><a href="about.html">About this document...</a></i> for information on suggesting changes.
261	</ADDRESS>
262	</BODY>
263	</HTML>