import re
import xml.sax.handler
def xml2obj(src):
"""
A simple function to converts XML data into native Python object.
"""
non_id_char = re.compile('[^_0-9a-zA-Z]')
def _name_mangle(name):
return non_id_char.sub('_', name)
class DataNode(object):
def __init__(self):
self._attrs = {} # XML attributes and child elements
self.data = None # child text data
def __len__(self):
# treat single element as a list of 1
return 1
def __getitem__(self, key):
if isinstance(key, basestring):
return self._attrs.get(key,None)
else:
return [self][key]
def __contains__(self, name):
return self._attrs.has_key(name)
def __nonzero__(self):
return bool(self._attrs or self.data)
def __getattr__(self, name):
if name.startswith('__'):
# need to do this for Python special methods???
raise AttributeError(name)
return self._attrs.get(name,None)
def _add_xml_attr(self, name, value):
if name in self._attrs:
# multiple attribute of the same name are represented by a list
children = self._attrs[name]
if not isinstance(children, list):
children = [children]
self._attrs[name] = children
children.append(value)
else:
self._attrs[name] = value
def __str__(self):
return self.data or ''
def __repr__(self):
items = sorted(self._attrs.items())
if self.data:
items.append(('data', self.data))
return u'{%s}' % ', '.join([u'%s:%s' % (k,repr(v)) for k,v in items])
class TreeBuilder(xml.sax.handler.ContentHandler):
def __init__(self):
self.stack = []
self.root = DataNode()
self.current = self.root
self.text_parts = []
def startElement(self, name, attrs):
self.stack.append((self.current, self.text_parts))
self.current = DataNode()
self.text_parts = []
# xml attributes --> python attributes
for k, v in attrs.items():
self.current._add_xml_attr(_name_mangle(k), v)
def endElement(self, name):
text = ''.join(self.text_parts).strip()
if text:
self.current.data = text
if self.current._attrs:
obj = self.current
else:
# a text only node is simply represented by the string
obj = text or ''
self.current, self.text_parts = self.stack.pop()
self.current._add_xml_attr(_name_mangle(name), obj)
def characters(self, content):
self.text_parts.append(content)
builder = TreeBuilder()
if isinstance(src,basestring):
xml.sax.parseString(src, builder)
else:
xml.sax.parse(src, builder)
return builder.root._attrs.values()[0]
