dict to xml and xml to dict

dict2xml.py

from xml.dom import minidom
from collections import Mapping
from petl.io import RowContainer
from lxml import etree


def fromxml(source, rowmatch, *args, **kwargs):
    return XmlView(source, rowmatch, *args, **kwargs)


class XmlView(RowContainer):
    def __init__(self, source, rowmatch, *args, **kwargs):
        self.source = source
        self.args = args
        self.rmatch = rowmatch

    def __iter__(self):
        context = etree.iterparse(self.source, events=('start','end'))
        _stack = []
        _data = ''
        for event, elem in context:
            tag = elem.tag
            if event == "start":
                _stack.append([elem.tag])
                #_data = elem.text
            elif event == "end":
                _data = elem.text
                last_tag = _stack.pop()
                if len(last_tag) == 1: #leaf
                    data = _data
                else:
                    if tag not in self.rmatch:
                        # build a dict, repeating pairs get pushed into lists
                        data = {}
                        for k, v in last_tag[1:]:
                            if k not in data:
                                data[k] = v
                            else:
                                el = data[k]
                                if type(el) is not list:
                                    data[k] = [el, v]
                                else:
                                    el.append(v)
                    else: #force into a list
                        res = dict(last_tag[1:])
                        #res = {k:v for k, v in last_tag[1:]}
                        #res = [{k:v} for k, v in last_tag[1:]]
                        yield res
                        #yield {tag:res}
                        data = ''
                if _stack:
                    _stack[-1].append((tag, data))
                else:
                    result = {tag:data}
                _data = ''
                elem.clear()


def dict2xml(structure, tostring=False):
    """将字典转换成xml的函数
        Args:
            structure: dict, 字典
            tostring: boolean, 是否输出未string, 或者doc
    """
    impl = minidom.getDOMImplementation()
    doc = impl.createDocument(None, 'shop', None)
    dict2element(doc.documentElement, structure, doc)
    return doc.documentElement.toxml() if tostring else doc


def dict2element(root, structure, doc):
    """
    Gets a dictionary like structure and converts its
    content into xml elements. After that appends
    resulted elements to root element. If root element
    is a string object creates a new elements with the
    given string and use that element as root.

    This function returns a xml element object.

    """
    assert isinstance(structure, Mapping), 'Structure must be a mapping object such as dict'

    # if root is a string make it a element
    if isinstance(root, str):
        root = doc.createElement(root)

    for key, value in structure.iteritems():
        if isinstance(value, Mapping):
            el = doc.createElement(str(key))
            dict2element(el, value, doc)
            root.appendChild(el)
        elif isinstance(value, list):
            for l in value:
                el = doc.createElement(str(key))
                dict2element(el, l, doc)
                root.appendChild(el)
        else:
            el = doc.createElement(str(key))
            if not value:
                txt = ''
            elif isinstance(value, unicode):
                txt = value.encode('utf8')
            else:
                txt = value
            el.appendChild(doc.createTextNode(txt))
            root.appendChild(el)
    return root
    

if __name__ == "__mian__":
    print dict2xml({"hell": 3, "world": "nimei"}, True)