How to convert an xml string to a dictionary?
This is a great module that someone created. I've used it several times. http://code.activestate.com/recipes/410469-xml-as-dictionary/
Here is the code from the website just in case the link goes bad.
from xml.etree import cElementTree as ElementTree
class XmlListConfig(list):
def __init__(self, aList):
for element in aList:
if element:
# treat like dict
if len(element) == 1 or element[0].tag != element[1].tag:
self.append(XmlDictConfig(element))
# treat like list
elif element[0].tag == element[1].tag:
self.append(XmlListConfig(element))
elif element.text:
text = element.text.strip()
if text:
self.append(text)
class XmlDictConfig(dict):
'''
Example usage:
>>> tree = ElementTree.parse('your_file.xml')
>>> root = tree.getroot()
>>> xmldict = XmlDictConfig(root)
Or, if you want to use an XML string:
>>> root = ElementTree.XML(xml_string)
>>> xmldict = XmlDictConfig(root)
And then use xmldict for what it is... a dict.
'''
def __init__(self, parent_element):
if parent_element.items():
self.update(dict(parent_element.items()))
for element in parent_element:
if element:
# treat like dict - we assume that if the first two tags
# in a series are different, then they are all different.
if len(element) == 1 or element[0].tag != element[1].tag:
aDict = XmlDictConfig(element)
# treat like list - we assume that if the first two tags
# in a series are the same, then the rest are the same.
else:
# here, we put the list in dictionary; the key is the
# tag name the list elements all share in common, and
# the value is the list itself
aDict = {element[0].tag: XmlListConfig(element)}
# if the tag has attributes, add those to the dict
if element.items():
aDict.update(dict(element.items()))
self.update({element.tag: aDict})
# this assumes that if you've got an attribute in a tag,
# you won't be having any text. This may or may not be a
# good idea -- time will tell. It works for the way we are
# currently doing XML configuration files...
elif element.items():
self.update({element.tag: dict(element.items())})
# finally, if there are no child tags and no attributes, extract
# the text
else:
self.update({element.tag: element.text})
Example usage:
tree = ElementTree.parse('your_file.xml')
root = tree.getroot()
xmldict = XmlDictConfig(root)
//Or, if you want to use an XML string:
root = ElementTree.XML(xml_string)
xmldict = XmlDictConfig(root)
The following XML-to-Python-dict snippet parses entities as well as attributes following this XML-to-JSON "specification". It is the most general solution handling all cases of XML.
from collections import defaultdict
def etree_to_dict(t):
d = {t.tag: {} if t.attrib else None}
children = list(t)
if children:
dd = defaultdict(list)
for dc in map(etree_to_dict, children):
for k, v in dc.items():
dd[k].append(v)
d = {t.tag: {k:v[0] if len(v) == 1 else v for k, v in dd.items()}}
if t.attrib:
d[t.tag].update(('@' + k, v) for k, v in t.attrib.items())
if t.text:
text = t.text.strip()
if children or t.attrib:
if text:
d[t.tag]['#text'] = text
else:
d[t.tag] = text
return d
It is used:
from xml.etree import cElementTree as ET
e = ET.XML('''
<root>
<e />
<e>text</e>
<e name="value" />
<e name="value">text</e>
<e> <a>text</a> <b>text</b> </e>
<e> <a>text</a> <a>text</a> </e>
<e> text <a>text</a> </e>
</root>
''')
from pprint import pprint
pprint(etree_to_dict(e))
The output of this example (as per above-linked "specification") should be:
{'root': {'e': [None,
'text',
{'@name': 'value'},
{'#text': 'text', '@name': 'value'},
{'a': 'text', 'b': 'text'},
{'a': ['text', 'text']},
{'#text': 'text', 'a': 'text'}]}}
Not necessarily pretty, but it is unambiguous, and simpler XML inputs result in simpler JSON. :)
Update
If you want to do the reverse, emit an XML string from a JSON/dict, you can use:
try:
basestring
except NameError: # python3
basestring = str
def dict_to_etree(d):
def _to_etree(d, root):
if not d:
pass
elif isinstance(d, basestring):
root.text = d
elif isinstance(d, dict):
for k,v in d.items():
assert isinstance(k, basestring)
if k.startswith('#'):
assert k == '#text' and isinstance(v, basestring)
root.text = v
elif k.startswith('@'):
assert isinstance(v, basestring)
root.set(k[1:], v)
elif isinstance(v, list):
for e in v:
_to_etree(e, ET.SubElement(root, k))
else:
_to_etree(v, ET.SubElement(root, k))
else:
raise TypeError('invalid type: ' + str(type(d)))
assert isinstance(d, dict) and len(d) == 1
tag, body = next(iter(d.items()))
node = ET.Element(tag)
_to_etree(body, node)
return ET.tostring(node)
pprint(dict_to_etree(d))
xmltodict (full disclosure: I wrote it) does exactly that:
xmltodict.parse("""
<?xml version="1.0" ?>
<person>
<name>john</name>
<age>20</age>
</person>""")
# {u'person': {u'age': u'20', u'name': u'john'}}