'''
XML2Py - XML to Python de-serialization
This code transforms an XML document into a Python data structure
Usage:
deserializer = XML2Py()
python_object = deserializer.parse( xml_string )
print xml_string
print python_object
'''
from lxml import etree
class XML2Py():
def __init__( self ):
self._parser = parser = etree.XMLParser( remove_blank_text=True )
self._root = None # root of etree structure
self.data = None # where we store the processed Python structure
def parse( self, xmlString ):
'''
processes XML string into Python data structure
'''
self._root = etree.fromstring( xmlString, self._parser )
self.data = self._parseXMLRoot()
return self.data
def tostring( self ):
'''
creates a string representation using our etree object
'''
if self._root != None:
return etree.tostring( self._root )
def _parseXMLRoot( self ):
'''
starts processing, takes care of first level idisyncrasies
'''
childDict = self._parseXMLNode( self._root )
return { self._root.tag : childDict["children"] }
def _parseXMLNode( self, element ):
'''
rest of the processing
'''
childContainer = None # either Dict or List
# process any tag attributes
# if we have attributes then the child container is a Dict
# otherwise a List
if element.items():
childContainer = {}
childContainer.update( dict( element.items() ) )
else:
childContainer = []
if element.text:
# tag with no attributes and one that contains text
childContainer.append( element.text )
else:
# tag might have children, let's process them
for child_elem in element.getchildren():
childDict = self._parseXMLNode( child_elem )
# let's store our child based on container type
#
if isinstance( childContainer, dict ):
# these children are lone tag entities ( eg, 'copyright' )
childContainer.update( { childDict["tag"] : childDict["children"] } )
else:
# these children are repeated tag entities ( eg, 'format' )
childContainer.append( childDict["children"] )
return { "tag":element.tag, "children": childContainer }
def main():
xml_string = '''
<documents>
<document date="June 6, 2009" title="The Newness of Python" author="John Doe">
<copyright type="CC" url="http://www.creativecommons.org/" date="June 24, 2009" />
<text>Python is very nice. Very, very nice.</text>
<formats>
<format type="pdf">
<info uri="http://www.python.org/newness-of-python.pdf" pages="245" />
</format>
<format type="web">
<info uri="http://www.python.org/newness-of-python.html" />
</format>
</formats>
</document>
</documents>
'''
deserializer = XML2Py()
python_object = deserializer.parse( xml_string )
print xml_string
print python_object
if __name__ == '__main__':
main()
