ASPN : Python Cookbook : xml reverse-engineering ElementTree code generator (*whew*)

import xml.etree.ElementTree as ET
import re

class ETGen(object):
TAGSUFFIX = 'XMLTag'
def __init__(self, xmlin, out, param={}):
self.counter = 0
self.constants = {}
self.lines = []

h = open(xmlin, 'r')
xml = h.read()
h.close()

builder = ET.XMLTreeBuilder()
builder.feed(xml)
tree = builder.close()

self.out = out

self.__walk(tree, None)
self.__write()

def __genName(self, name):
self.counter += 1
return re.search('(?:{.*?})?(.*)', name).group(1) + ETGen.TAGSUFFIX + str(self.counter)

def __write(self):
h = open(self.out, 'w')
h.write("import xml.etree.ElementTree as ET\n\n")

# prints namespace constants
h.writelines(["%s = '%s'\n" % (v, k) for k, v in self.constants.items()])
h.write("\n")

h.write("def build(**kwargs):\n\t")

h.write("\n\t".join(self.lines))
h.write("\n\treturn ET.tostring(%s)\n\n" % self.root)

h.write("if __name__ == '__main__': print build()")
h.close()

def __getNamespace(self, name):
ns = re.search('(?:{(.*?)})?(.*)', name).group(1)
if ns is None:
return '\'%s\'' % name
if ns not in self.constants:
nsName = "NS" + str(len(self.constants))
self.constants[ns] = nsName
else:
nsName = self.constants[ns]
tag = re.sub('{.*?}(.*)', '\'{%%s}\\1\' %% %s' % nsName, name)
return tag

def __walk(self, node, parent):
name = self.__genName(node.tag)
tag = self.__getNamespace(node.tag)

if parent is None:
self.root = name
self.lines.append("%s = ET.Element(%s)" % (name, tag))
else:
self.lines.append("%s = ET.SubElement(%s, %s)" % (name, parent, tag))

# handles text
try:
t = node.text.strip()
if t == '': t = None
except:
t = None

if t is not None:
self.lines.append("%s.text = kwargs.get('', '%s') # PARAMETERIZE" % (name, t))

# handles attributes
for key,val in node.items():
key = self.__getNamespace(key)
self.lines.append("%s.set(%s, kwargs.get('', '%s')) # PARAMETERIZE" % (name, key, val))
for i in node.getchildren():
self.__walk(i, name)

def main():
g = ETGen('/home/user/manifest.xml', '/home/user/manifest_generator.py')

if __name__ == '__main__': main()