import re
from elementtree import ElementTree as ET
def main():
# Some sample data from http://developer.yahoo.com/maps/rest/V1/geocode.html
yahoo_geocode_test = """\
<?xml version="1.0" encoding="UTF-8"?>
<ResultSet xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="urn:yahoo:maps"
xsi:schemaLocation="urn:yahoo:maps http://api.local.yahoo.com/MapsService/V1/GeocodeResponse.xsd">
<Result precision="address">
<Latitude>37.416384</Latitude>
<Longitude>-122.024853</Longitude>
<Address>701 FIRST AVE</Address>
<City>SUNNYVALE</City>
<State>CA</State>
<Zip>94089-1019</Zip>
<Country>US</Country>
</Result>
</ResultSet>
"""
# The "ResultSet" element should be treated like a list
# The "Result" element should be treated like a map, with the
# child elements converted to key/value pairs
tag_convert = {"ResultSet": list_of_children,
"Result": children_are_mapping}
doc = ET.fromstring(yahoo_geocode_test)
xdata = XMLDataExtractor(tag_convert,
no_ns=True, downcase=True)
result = xdata.from_elem(doc)
from pprint import pprint
pprint(result)
"""
Result:
[{'address': '701 FIRST AVE',
'city': 'SUNNYVALE',
'country': 'US',
'latitude': '37.416384',
'longitude': '-122.024853',
'state': 'CA',
'zip': '94089-1019'}]
"""
def identity(trans, elem):
"""Return 'elem' unchanged"""
return elem
def attr_are_mapping(trans, elem):
"""The attributes of 'elem' contain it's key/value pairs"""
return dict(elem.attrib)
def list_of_children(trans, elem):
"""Child elements of 'elem' are returned as a list"""
return map(trans.from_elem, elem)
def children_are_mapping(trans, elem):
"""Child elements of elem are the key/value pairs. tag name is
key, value is inner text"""
res = {}
for i in elem:
key = trans.tagnorm(i)
if len(i):
value = trans.from_elem(i)
else:
value = i.text
res[key] = value
return res
def children_and_attr(trans, elem):
"""Child elements of 'elem', as well as it's attributes, as the
resulting key/value pairs"""
res = children_are_mapping(trans, elem)
res.update(elem.attrib)
return res
class XMLDataExtractor:
STRIP_NS = re.compile(r"{.*}")
def __init__(self, tag_convert, no_ns=False, downcase=False):
"""
tag_convert: a map from tag names to conversion functions
no_ns: if True, ignore namespaces
downcase: downcase all resulting tag names
"""
self.no_ns = no_ns
self.downcase = downcase
tag_convert_norm = {}
for k,v in tag_convert.items():
tag_convert_norm[self.tagnorm(k)] = v
self.tag_convert = tag_convert_norm
def from_elem(self, elem):
"Convert this element to a useful datastructure"
fn = self.tag_convert.get(self.tagnorm(elem), identity)
return fn(self, elem)
def tagnorm(self, tag_or_elem):
"""Normalize the tag name, optionally stripping namespaces and
downcasing. 'elem' may be an Element or a string"""
if ET.iselement(tag_or_elem):
tag = tag_or_elem.tag
else:
tag = tag_or_elem
if self.no_ns:
res = self.STRIP_NS.sub('', tag)
else:
res = tag
if self.downcase:
res = res.lower()
return res
if __name__ == "__main__": main()
