Module pyclasslookup

A whole-tree Element class lookup scheme for lxml.etree.

This class lookup scheme allows access to the entire XML tree in read-only mode. To use it, let a class inherit from PythonElementClassLookup and re-implement the lookup(self, doc, root) method:

>>> from lxml import etree, pyclasslookup
>>>
>>> class MyElementClass(etree.ElementBase):
...     honkey = True
...
>>> class MyLookup(pyclasslookup.PythonElementClassLookup):
...     def lookup(self, doc, root):
...         if root.tag == "sometag":
...             return MyElementClass
...         else:
...             for child in root:
...                 if child.tag == "someothertag":
...                     return MyElementClass
...         # delegate to default
...         return None

Note that the API of the Element objects is not complete. It is purely read-only and does not support all features of the normal lxml.etree API (such as XPath, extended slicing or some iteration methods).

Also, you cannot wrap such a read-only Element in an ElementTree, and you must take care not to keep a reference to them outside of the lookup() method.

See /element_classes.html