~ubuntu-branches/debian/wheezy/lxml/wheezy

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to:</a></li></ul></li></ul></li></ul></div><h1 class="title">lxml.objectify</h1>

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foreign" id="sax-menu"><li class="menu title"><a href="sax.html">Sax support</a><ul class="submenu"><li class="menu item"><a href="sax.html#building-a-tree-from-sax-events">Building a tree from SAX events</a></li><li class="menu item"><a href="sax.html#producing-sax-events-from-an-elementtree-or-element">Producing SAX events from an ElementTree or Element</a></li><li class="menu item"><a href="sax.html#interfacing-with-pulldom-minidom">Interfacing with pulldom/minidom</a></li></ul></li></ul><ul class="menu foreign" id="capi-menu"><li class="menu title"><a href="capi.html">The public C-API of lxml.etree</a><ul class="submenu"><li class="menu item"><a href="capi.html#writing-external-modules-in-cython">Writing external modules in Cython</a></li><li class="menu item"><a href="capi.html#writing-external-modules-in-c">Writing external modules in C</a></li></ul></li></ul></li></ul><ul id="Developing lxml-section"><li>Developing lxml<ul class="menu foreign" id="build-menu"><li class="menu title"><a href="build.html">How to build lxml from source</a><ul class="submenu"><li class="menu item"><a href="build.html#cython">Cython</a></li><li class="menu item"><a href="build.html#subversion">Subversion</a></li><li class="menu item"><a href="build.html#setuptools">Setuptools</a></li><li class="menu item"><a href="build.html#running-the-tests-and-reporting-errors">Running the tests and reporting errors</a></li><li class="menu item"><a href="build.html#building-an-egg">Building an egg</a></li><li class="menu item"><a href="build.html#building-lxml-on-macos-x">Building lxml on MacOS-X</a></li><li class="menu item"><a href="build.html#static-linking-on-windows">Static linking on Windows</a></li><li class="menu item"><a href="build.html#building-debian-packages-from-svn-sources">Building Debian packages from SVN sources</a></li></ul></li></ul><ul class="menu foreign" id="lxml source howto-menu"><li class="menu title"><a href="lxml-source-howto.html">How to read the source of lxml</a><ul class="submenu"><li class="menu item"><a href="lxml-source-howto.html#what-is-cython">What is Cython?</a></li><li class="menu item"><a href="lxml-source-howto.html#where-to-start">Where to start?</a></li><li class="menu item"><a href="lxml-source-howto.html#lxml-etree">lxml.etree</a></li><li class="menu item"><a href="lxml-source-howto.html#python-modules">Python modules</a></li><li class="menu item"><a href="lxml-source-howto.html#lxml-objectify">lxml.objectify</a></li><li class="menu item"><a href="lxml-source-howto.html#lxml-html">lxml.html</a></li></ul></li></ul><ul class="menu foreign" id="changes 2 2 6-menu"><li class="menu title"><a href="changes-2.2.6.html">Release Changelog</a></li></ul><ul class="menu foreign" id="credits-menu"><li class="menu title"><a href="credits.html">Credits</a><ul class="submenu"><li class="menu item"><a href="credits.html#main-contributors">Main contributors</a></li><li class="menu item"><a href="credits.html#special-thanks-goes-to">Special thanks goes to:</a></li></ul></li></ul></li></ul></div><h1 class="title">lxml.objectify</h1>

<li><a class="reference internal" href="#what-is-different-from-lxml-etree" id="id17">What is different from lxml.etree?</a></li>

</ul>

</div>

To set up and use <tt class="docutils literal">objectify</tt>, you need both the <tt class="docutils literal">lxml.etree</tt>

module and <tt class="docutils literal">lxml.objectify</tt>:

To set up and use <tt class="docutils literal">objectify</tt>, you need both the <tt class="docutils literal">lxml.etree</tt>

module and <tt class="docutils literal">lxml.objectify</tt>:

<div class="syntax"><pre>>>> from lxml import etree

>>> from lxml import objectify

</pre></div>

The objectify API is very different from the ElementTree API. If it

is used, it should not be mixed with other element implementations

(such as trees parsed with <tt class="docutils literal">lxml.etree</tt>), to avoid non-obvious

(such as trees parsed with <tt class="docutils literal">lxml.etree</tt>), to avoid non-obvious

behaviour.

The <a class="reference external" href="performance.html#lxml-objectify">benchmark page</a> has some hints on performance optimisation of

code using lxml.objectify.

formatting of XML output.

<h1>The lxml.objectify API</h1>

In <tt class="docutils literal">lxml.objectify</tt>, element trees provide an API that models the behaviour

In <tt class="docutils literal">lxml.objectify</tt>, element trees provide an API that models the behaviour

of normal Python object trees as closely as possible.

<h2>Creating objectify trees</h2>

As with <tt class="docutils literal">lxml.etree</tt>, you can either create an <tt class="docutils literal">objectify</tt> tree by

As with <tt class="docutils literal">lxml.etree</tt>, you can either create an <tt class="docutils literal">objectify</tt> tree by

parsing an XML document or by building one from scratch. To parse a

document, just use the <tt class="docutils literal">parse()</tt> or <tt class="docutils literal">fromstring()</tt> functions of

document, just use the <tt class="docutils literal">parse()</tt> or <tt class="docutils literal">fromstring()</tt> functions of

the module:

<div class="syntax"><pre>>>> fileobject = StringIO('<test/>')

>>> print(isinstance(root, objectify.ObjectifiedElement))

True

</pre></div>

To build a new tree in memory, <tt class="docutils literal">objectify</tt> replicates the standard

factory function <tt class="docutils literal">Element()</tt> from <tt class="docutils literal">lxml.etree</tt>:

To build a new tree in memory, <tt class="docutils literal">objectify</tt> replicates the standard

factory function <tt class="docutils literal">Element()</tt> from <tt class="docutils literal">lxml.etree</tt>:

<div class="syntax"><pre>>>> obj_el = objectify.Element("new")

>>> print(isinstance(obj_el, objectify.ObjectifiedElement))

100

True

105

</pre></div>

106

New subelements will automatically inherit the objectify behaviour

107

from their tree. However, all independent elements that you create

108

through the <tt class="docutils literal">Element()</tt> factory of lxml.etree (instead of objectify)

109

will not support the <tt class="docutils literal">objectify</tt> API by themselves:

108

through the <tt class="docutils literal">Element()</tt> factory of lxml.etree (instead of objectify)

109

will not support the <tt class="docutils literal">objectify</tt> API by themselves:

110

<div class="syntax"><pre>>>> subel = etree.SubElement(obj_el, "sub")

111

>>> print(isinstance(subel, objectify.ObjectifiedElement))

112

True

118

</div>

119

120

<h2>Element access through object attributes</h2>

121

The main idea behind the <tt class="docutils literal">objectify</tt> API is to hide XML element access

121

The main idea behind the <tt class="docutils literal">objectify</tt> API is to hide XML element access

122

behind the usual object attribute access pattern. Asking an element for an

123

attribute will return the sequence of children with corresponding tag names:

124

<div class="syntax"><pre>>>> root = objectify.Element("root")

161

['x', 'x']

162

</pre></div>

163

If you want to iterate over all children or need to provide a specific

164

namespace for the tag, use the <tt class="docutils literal">iterchildren()</tt> method. Like the other

164

namespace for the tag, use the <tt class="docutils literal">iterchildren()</tt> method. Like the other

165

methods for iteration, it supports an optional tag keyword argument:

166

<div class="syntax"><pre>>>> [ el.tag for el in root.iterchildren() ]

167

['b', 'x', 'x']

264

<how-many py:pytype="int">5</how-many>

265

</root>

266

</pre></div>

267

<tt class="docutils literal">objectify.E</tt> is an instance of <tt class="docutils literal">objectify.ElementMaker</tt>. By default, it

267

<tt class="docutils literal">objectify.E</tt> is an instance of <tt class="docutils literal">objectify.ElementMaker</tt>. By default, it

268

creates pytype annotated Elements without a namespace. You can switch off the

269

pytype annotation by passing False to the <tt class="docutils literal">annotate</tt> keyword argument of the

270

constructor. You can also pass a default namespace and an <tt class="docutils literal">nsmap</tt>:

269

pytype annotation by passing False to the <tt class="docutils literal">annotate</tt> keyword argument of the

270

constructor. You can also pass a default namespace and an <tt class="docutils literal">nsmap</tt>:

271

<div class="syntax"><pre>>>> myE = objectify.ElementMaker(annotate=False,

272

... namespace="http://my/ns", nsmap={None : "http://my/ns"})

273

291

>>> print(root.b.tag)

292

{http://ns/}b

293

</pre></div>

294

Note that the <tt class="docutils literal">SubElement()</tt> factory of <tt class="docutils literal">lxml.etree</tt> does not

294

Note that the <tt class="docutils literal">SubElement()</tt> factory of <tt class="docutils literal">lxml.etree</tt> does not

295

inherit any namespaces when creating a new subelement. Element

296

creation must be explicit about the namespace, and is simplified

297

through the E-factory as described above.

305

AttributeError: no such child: {http://ns/}c

306

</pre></div>

307

To access an element in a different namespace than its parent, you can

308

use <tt class="docutils literal">getattr()</tt>:

308

use <tt class="docutils literal">getattr()</tt>:

309

<div class="syntax"><pre>>>> c = getattr(root, "{http://other/}c")

310

>>> print(c.tag)

311

{http://other/}c

376

>>> schema = etree.XMLSchema(file=f)

377

</pre></div>

378

When creating the validating parser, we must make sure it <a class="reference external" href="#advance-element-class-lookup">returns

379

objectify trees</a>. This is best done with the <tt class="docutils literal">makeparser()</tt>

379

objectify trees</a>. This is best done with the <tt class="docutils literal">makeparser()</tt>

380

function:

381

<div class="syntax"><pre>>>> parser = objectify.makeparser(schema = schema)

382

</pre></div>

399

400

<h1>ObjectPath</h1>

401

For both convenience and speed, objectify supports its own path language,

402

represented by the <tt class="docutils literal">ObjectPath</tt> class:

402

represented by the <tt class="docutils literal">ObjectPath</tt> class:

403

404

>>> b1 = etree.SubElement(root, "{http://ns/}b")

405

>>> c = etree.SubElement(b1, "{http://ns/}c")

505

>>> [ el.text for el in path.find(root) ]

506

['my value', 'my new value']

507

</pre></div>

508

As with attribute assignment, <tt class="docutils literal">setattr()</tt> accepts lists:

508

As with attribute assignment, <tt class="docutils literal">setattr()</tt> accepts lists:

509

<div class="syntax"><pre>>>> path.setattr(root, ["v1", "v2", "v3"])

510

511

['v1', 'v2', 'v3']

519

...

520

TypeError: creating indexed path attributes is not supported

521

</pre></div>

522

It is worth noting that ObjectPath does not depend on the <tt class="docutils literal">objectify</tt> module

522

It is worth noting that ObjectPath does not depend on the <tt class="docutils literal">objectify</tt> module

523

or the ObjectifiedElement implementation. It can also be used in combination

524

with Elements from the normal lxml.etree API.

525

</div>

556

1234 - 12345

557

</pre></div>

558

However, data elements continue to provide the objectify API. This means that

559

sequence operations such as <tt class="docutils literal">len()</tt>, slicing and indexing (e.g. of strings)

559

sequence operations such as <tt class="docutils literal">len()</tt>, slicing and indexing (e.g. of strings)

560

cannot behave as the Python types. Like all other tree elements, they show

561

the normal slicing behaviour of objectify elements:

562

<div class="syntax"><pre>>>> root = objectify.fromstring("<root><a>test</a>toast</root>")

576

</pre></div>

577

If you need to run sequence operations on data types, you must ask the API for

578

the real Python value. The string value is always available through the

579

normal ElementTree <tt class="docutils literal">.text</tt> attribute. Additionally, all data classes

580

provide a <tt class="docutils literal">.pyval</tt> attribute that returns the value as plain Python type:

579

normal ElementTree <tt class="docutils literal">.text</tt> attribute. Additionally, all data classes

580

provide a <tt class="docutils literal">.pyval</tt> attribute that returns the value as plain Python type:

581

<div class="syntax"><pre>>>> root = objectify.fromstring("<root><a>test</a>5</root>")

582

>>> root.a.text

583

'test'

607

>>> print(root.a.pyval)

608

25

609

</pre></div>

610

In other words, <tt class="docutils literal">objectify</tt> data elements behave like immutable Python

610

In other words, <tt class="docutils literal">objectify</tt> data elements behave like immutable Python

611

types. You can replace them, but not modify them.

612

613

<h2>Recursive tree dump</h2>

614

To see the data types that are currently used, you can call the module level

615

<tt class="docutils literal">dump()</tt> function that returns a recursive string representation for

615

<tt class="docutils literal">dump()</tt> function that returns a recursive string representation for

616

elements:

617

<div class="syntax"><pre>>>> root = objectify.fromstring("""

618

... <root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

716

Objectify uses two different types of Elements. Structural Elements (or tree

717

Elements) represent the object tree structure. Data Elements represent the

718

data containers at the leafs. You can explicitly create tree Elements with

719

the <tt class="docutils literal">objectify.Element()</tt> factory and data Elements with the

720

<tt class="docutils literal">objectify.DataElement()</tt> factory.

719

the <tt class="docutils literal">objectify.Element()</tt> factory and data Elements with the

720

<tt class="docutils literal">objectify.DataElement()</tt> factory.

721

When Element objects are created, lxml.objectify must determine which

722

implementation class to use for them. This is relatively easy for tree

723

Elements and less so for data Elements. The algorithm is as follows:

734

<li>Otherwise, use the default class for empty data classes.</li>

735

</ol>

736

You can change the default classes for tree Elements and empty data Elements

737

at setup time. The <tt class="docutils literal">ObjectifyElementClassLookup()</tt> call accepts two keyword

738

arguments, <tt class="docutils literal">tree_class</tt> and <tt class="docutils literal">empty_data_class</tt>, that determine the Element

739

classes used in these cases. By default, <tt class="docutils literal">tree_class</tt> is a class called

740

<tt class="docutils literal">ObjectifiedElement</tt> and <tt class="docutils literal">empty_data_class</tt> is a <tt class="docutils literal">StringElement</tt>.

737

at setup time. The <tt class="docutils literal">ObjectifyElementClassLookup()</tt> call accepts two keyword

738

arguments, <tt class="docutils literal">tree_class</tt> and <tt class="docutils literal">empty_data_class</tt>, that determine the Element

739

classes used in these cases. By default, <tt class="docutils literal">tree_class</tt> is a class called

740

<tt class="docutils literal">ObjectifiedElement</tt> and <tt class="docutils literal">empty_data_class</tt> is a <tt class="docutils literal">StringElement</tt>.

741

742

<h2>Type annotations</h2>

743

The "type hint" mechanism deploys an XML attribute defined as

744

<tt class="docutils literal">lxml.objectify.PYTYPE_ATTRIBUTE</tt>. It may contain any of the following

744

<tt class="docutils literal">lxml.objectify.PYTYPE_ATTRIBUTE</tt>. It may contain any of the following

745

string values: int, long, float, str, unicode, NoneType:

746

<div class="syntax"><pre>>>> print(objectify.PYTYPE_ATTRIBUTE)

747

{http://codespeak.net/lxml/objectify/pytype}pytype

763

None

764

</pre></div>

765

Note that you can change the name and namespace used for this

766

attribute through the <tt class="docutils literal">set_pytype_attribute_tag(tag)</tt> module

766

attribute through the <tt class="docutils literal">set_pytype_attribute_tag(tag)</tt> module

767

function, in case your application ever needs to. There is also a

768

utility function <tt class="docutils literal">annotate()</tt> that recursively generates this

768

utility function <tt class="docutils literal">annotate()</tt> that recursively generates this

769

attribute for the elements of a tree:

770

<div class="syntax"><pre>>>> root = objectify.fromstring("<root><a>test</a>5</root>")

771

>>> print(objectify.dump(root))

805

s = '5' [StringElement]

806

* xsi:type = 'xsd:string'

807

</pre></div>

808

Again, there is a utility function <tt class="docutils literal">xsiannotate()</tt> that recursively

808

Again, there is a utility function <tt class="docutils literal">xsiannotate()</tt> that recursively

809

generates the "xsi:type" attribute for the elements of a tree:

810

<div class="syntax"><pre>>>> root = objectify.fromstring('''\

811

... <root><a>test</a>5<c>true</c></root>

827

c = True [BoolElement]

828

* xsi:type = 'xsd:boolean'

829

</pre></div>

830

Note, however, that <tt class="docutils literal">xsiannotate()</tt> will always use the first XML Schema

830

Note, however, that <tt class="docutils literal">xsiannotate()</tt> will always use the first XML Schema

831

datatype that is defined for any given Python type, see also

832

<a class="reference internal" href="#defining-additional-data-classes">Defining additional data classes</a>.

833

The utility function <tt class="docutils literal">deannotate()</tt> can be used to get rid of 'py:pytype'

833

The utility function <tt class="docutils literal">deannotate()</tt> can be used to get rid of 'py:pytype'

834

and/or 'xsi:type' information:

835

<div class="syntax"><pre>>>> root = objectify.fromstring('''\

836

... <root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

860

</pre></div>

861

You can control which type attributes should be de-annotated with the keyword

862

arguments 'pytype' (default: True) and 'xsi' (default: True).

863

<tt class="docutils literal">deannotate()</tt> can also remove 'xsi:nil' attributes by setting 'xsi_nil=True'

863

<tt class="docutils literal">deannotate()</tt> can also remove 'xsi:nil' attributes by setting 'xsi_nil=True'

864

(default: False):

865

<div class="syntax"><pre>>>> root = objectify.fromstring('''\

866

... <root xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

896

</div>

897

898

<h2>The DataElement factory</h2>

899

For convenience, the <tt class="docutils literal">DataElement()</tt> factory creates an Element with a

899

For convenience, the <tt class="docutils literal">DataElement()</tt> factory creates an Element with a

900

Python value in one step. You can pass the required Python type name or the

901

XSI type name:

902

920

* py:pytype = 'int'

921

* xsi:type = 'xsd:integer'

922

</pre></div>

923

XML Schema types reside in the XML schema namespace thus <tt class="docutils literal">DataElement()</tt>

923

XML Schema types reside in the XML schema namespace thus <tt class="docutils literal">DataElement()</tt>

924

tries to correctly prefix the xsi:type attribute value for you:

925

926

>>> root.s = objectify.DataElement(5, _xsi="string")

931

932

</root>

933

</pre></div>

934

<tt class="docutils literal">DataElement()</tt> uses a default nsmap to set these prefixes:

934

<tt class="docutils literal">DataElement()</tt> uses a default nsmap to set these prefixes:

935

<div class="syntax"><pre>>>> el = objectify.DataElement('5', _xsi='string')

936

>>> namespaces = list(el.nsmap.items())

937

>>> namespaces.sort()

995

</pre></div>

996

It is your responsibility to fix the prefixes of attribute values if you

997

choose to deviate from the standard prefixes. A convenient way to do this for

998

xsi:type attributes is to use the <tt class="docutils literal">xsiannotate()</tt> utility:

998

xsi:type attributes is to use the <tt class="docutils literal">xsiannotate()</tt> utility:

999

<div class="syntax"><pre>>>> objectify.xsiannotate(root)

1000

>>> print(etree.tostring(root, pretty_print=True))

1001

1009

<h2>Defining additional data classes</h2>

1010

You can plug additional data classes into objectify that will be used in

1011

exactly the same way as the predefined types. Data classes can either inherit

1012

from <tt class="docutils literal">ObjectifiedDataElement</tt> directly or from one of the specialised

1013

classes like <tt class="docutils literal">NumberElement</tt> or <tt class="docutils literal">BoolElement</tt>. The numeric types require

1014

an initial call to the NumberElement method <tt class="docutils literal">self._setValueParser(function)</tt>

1012

from <tt class="docutils literal">ObjectifiedDataElement</tt> directly or from one of the specialised

1013

classes like <tt class="docutils literal">NumberElement</tt> or <tt class="docutils literal">BoolElement</tt>. The numeric types require

1014

an initial call to the NumberElement method <tt class="docutils literal">self._setValueParser(function)</tt>

1015

to set their type conversion function (string -> numeric Python type). This

1016

call should be placed into the element <tt class="docutils literal">_init()</tt> method.

1017

The registration of data classes uses the <tt class="docutils literal">PyType</tt> class:

1016

call should be placed into the element <tt class="docutils literal">_init()</tt> method.

1017

The registration of data classes uses the <tt class="docutils literal">PyType</tt> class:

1018

<div class="syntax"><pre>>>> class ChristmasDate(objectify.ObjectifiedDataElement):

1019

... def call_santa(self):

1020

... print("Ho ho ho!")

1029

check and the custom data class. If a type check is provided it must accept a

1030

string as argument and raise ValueError or TypeError if it cannot handle the

1031

string value.

1032

PyTypes are used if an element carries a <tt class="docutils literal">py:pytype</tt> attribute denoting its

1032

PyTypes are used if an element carries a <tt class="docutils literal">py:pytype</tt> attribute denoting its

1033

data type or, in absence of such an attribute, if the given type check callable

1034

does not raise a ValueError/TypeError exception when applied to the element

1035

text.

1036

If you want, you can also register this type under an XML Schema type name:

1037

<div class="syntax"><pre>>>> xmas_type.xmlSchemaTypes = ("date",)

1038

</pre></div>

1039

XML Schema types will be considered if the element has an <tt class="docutils literal">xsi:type</tt>

1039

XML Schema types will be considered if the element has an <tt class="docutils literal">xsi:type</tt>

1040

attribute that specifies its data type. The line above binds the XSD type

1041

<tt class="docutils literal">date</tt> to the newly defined Python type. Note that this must be done before

1041

<tt class="docutils literal">date</tt> to the newly defined Python type. Note that this must be done before

1042

the next step, which is to register the type. Then you can use it:

1043

<div class="syntax"><pre>>>> xmas_type.register()

1044

1052

AttributeError: no such child: call_santa

1053

</pre></div>

1054

If you need to specify dependencies between the type check functions, you can

1055

pass a sequence of type names through the <tt class="docutils literal">before</tt> and <tt class="docutils literal">after</tt> keyword

1056

arguments of the <tt class="docutils literal">register()</tt> method. The PyType will then try to register

1055

pass a sequence of type names through the <tt class="docutils literal">before</tt> and <tt class="docutils literal">after</tt> keyword

1056

arguments of the <tt class="docutils literal">register()</tt> method. The PyType will then try to register

1057

itself before or after the respective types, as long as they are currently

1058

registered. Note that this only impacts the currently registered types at the

1059

time of registration. Types that are registered later on will not care about

1070

>>> root.a.call_santa()

1071

Ho ho ho!

1072

</pre></div>

1073

To unregister a type, call its <tt class="docutils literal">unregister()</tt> method:

1073

To unregister a type, call its <tt class="docutils literal">unregister()</tt> method:

1074

<div class="syntax"><pre>>>> root.a.call_santa()

1075

Ho ho ho!

1076

>>> xmas_type.unregister()

1086

1087

<h2>Advanced element class lookup</h2>

1088

In some cases, the normal data class setup is not enough. Being based

1089

on <tt class="docutils literal">lxml.etree</tt>, however, <tt class="docutils literal">lxml.objectify</tt> supports very

1089

on <tt class="docutils literal">lxml.etree</tt>, however, <tt class="docutils literal">lxml.objectify</tt> supports very

1090

fine-grained control over the Element classes used in a tree. All you

1091

have to do is configure a different <a class="reference external" href="element_classes.html">class lookup</a> mechanism (or

1092

write one yourself).

1111

support for <a class="reference external" href="element_classes.html#namespace-class-lookup">namespace specific classes</a>, you can register the

1112

objectify lookup as a fallback of the namespace lookup. In this case,

1113

however, you have to take care that the namespace classes inherit from

1114

<tt class="docutils literal">objectify.ObjectifiedElement</tt>, not only from the normal

1115

<tt class="docutils literal">lxml.etree.ElementBase</tt>, so that they support the <tt class="docutils literal">objectify</tt>

1114

<tt class="docutils literal">objectify.ObjectifiedElement</tt>, not only from the normal

1115

<tt class="docutils literal">lxml.etree.ElementBase</tt>, so that they support the <tt class="docutils literal">objectify</tt>

1116

API. The above setup code then becomes:

1117

<div class="syntax"><pre>>>> lookup = etree.ElementNamespaceClassLookup(

1118

... objectify.ObjectifyElementClassLookup() )

1128

1129

<li>len(<element>) returns the sibling count, not the number of children of

1130

<element>. You can retrieve the number of children with the

1131

<tt class="docutils literal">countchildren()</tt> method.</li>

1131

<tt class="docutils literal">countchildren()</tt> method.</li>

1132

<li>Iteration over elements does not yield the children, but the siblings. You

1133

can access all children with the <tt class="docutils literal">iterchildren()</tt> method on elements or

1134

retrieve a list by calling the <tt class="docutils literal">getchildren()</tt> method.</li>

1133

can access all children with the <tt class="docutils literal">iterchildren()</tt> method on elements or

1134

retrieve a list by calling the <tt class="docutils literal">getchildren()</tt> method.</li>

1135

<li>The find, findall and findtext methods require a different implementation

1136

based on ETXPath. In <tt class="docutils literal">lxml.etree</tt>, they use a Python implementation based

1136

based on ETXPath. In <tt class="docutils literal">lxml.etree</tt>, they use a Python implementation based

1137

on the original iteration scheme. This has the disadvantage that they may

1138

not be 100% backwards compatible, and the additional advantage that they now

1139

support any XPath expression.</li>

1142

</div>

1143

1144

1145

Generated on: 2009-11-11.

1145

Generated on: 2010-03-02.

1146

1147

</div>

1148

</body>

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