mirror of
https://github.com/kennethreitz/python-guide.git
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Max Weiner
111 lines
2.6 KiB
ReStructuredText
111 lines
2.6 KiB
ReStructuredText
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###########
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XML parsing
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###########
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.. image:: /_static/photos/33888714601_a1f7d020a2_k_d.jpg
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********
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untangle
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********
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`untangle <https://github.com/stchris/untangle>`_ is a simple library which
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takes an XML document and returns a Python object which mirrors the nodes and
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attributes in its structure.
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For example, an XML file like this:
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.. code-block:: xml
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<?xml version="1.0"?>
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<root>
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<child name="child1">
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</root>
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can be loaded like this:
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.. code-block:: python
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import untangle
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obj = untangle.parse('path/to/file.xml')
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and then you can get the child element's name attribute like this:
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.. code-block:: python
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obj.root.child['name']
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untangle also supports loading XML from a string or a URL.
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*********
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xmltodict
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*********
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`xmltodict <https://github.com/martinblech/xmltodict>`_ is another simple
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library that aims at making XML feel like working with JSON.
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An XML file like this:
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.. code-block:: xml
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<mydocument has="an attribute">
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<and>
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<many>elements</many>
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<many>more elements</many>
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</and>
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<plus a="complex">
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element as well
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</plus>
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</mydocument>
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can be loaded into a Python dict like this:
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.. code-block:: python
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import xmltodict
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with open('path/to/file.xml') as fd:
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doc = xmltodict.parse(fd.read())
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and then you can access elements, attributes, and values like this:
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.. code-block:: python
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doc['mydocument']['@has'] # == u'an attribute'
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doc['mydocument']['and']['many'] # == [u'elements', u'more elements']
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doc['mydocument']['plus']['@a'] # == u'complex'
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doc['mydocument']['plus']['#text'] # == u'element as well'
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xmltodict also lets you roundtrip back to XML with the unparse function,
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has a streaming mode suitable for handling files that don't fit in memory,
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and supports XML namespaces.
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**********
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xmlschema
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**********
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`xmlschema <https://github.com/sissaschool/xmlschema>`_ provides support for using XSD-Schemas in Python.
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Unlike other XML libraries, automatic type parsing is available, so f.e. if the schema defines an element to be of type ``int``, the parsed ``dict`` will contain also an ``int`` value for that element.
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Moreover the library supports automatic and explicit validation of XML documents against a schema.
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.. code-block:: python
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from xmlschema import XMLSchema, etree_tostring
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# load a XSD schema file
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schema = XMLSchema("your_schema.xsd")
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# validate against the schema
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schema.validate("your_file.xml")
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# or
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schema.is_valid("your_file.xml")
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# decode a file
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data = schmema.decode("your_file.xml")
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# encode to string
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s = etree_tostring(schema.encode(data))
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