xml.etree.ElementTree vs. lxml

下面是两个最常用的库的一些优点，在进行选择之前，我应该了解它们。

xml.etree.ElementTree:

来自标准库:不需要安装任何模块

lxml

轻松编写XML声明:例如，您是否需要添加standalone="no"? 漂亮的打印:无需额外代码就可以得到漂亮的缩进XML。 Objectify功能:它允许您像处理普通的Python对象hierarchy.node一样使用XML。 sourceline允许您轻松地获取正在使用的XML元素的行。 您还可以使用内置的XSD模式检查器。

XML:

<foo>
   <bar>
      <type foobar="1"/>
      <type foobar="2"/>
   </bar>
</foo>

Python代码:

import xml.etree.cElementTree as ET

tree = ET.parse("foo.xml")
root = tree.getroot() 
root_tag = root.tag
print(root_tag) 

for form in root.findall("./bar/type"):
    x=(form.attrib)
    z=list(x)
    for i in z:
        print(x[i])

输出:

foo
1
2

我很受伤，没有人建议熊猫。Pandas有一个read_xml()函数，它非常适合这种扁平的xml结构。

import pandas as pd

xml = """<foo>
   <bar>
      <type foobar="1"/>
      <type foobar="2"/>
   </bar>
</foo>"""

df = pd.read_xml(xml, xpath=".//type")
print(df)

输出:

   foobar
0       1
1       2

为了简单起见，我建议使用xmltodict。

它将XML解析为OrderedDict;

>>> e = '<foo>
             <bar>
                 <type foobar="1"/>
                 <type foobar="2"/>
             </bar>
        </foo> '

>>> import xmltodict
>>> result = xmltodict.parse(e)
>>> result

OrderedDict([(u'foo', OrderedDict([(u'bar', OrderedDict([(u'type', [OrderedDict([(u'@foobar', u'1')]), OrderedDict([(u'@foobar', u'2')])])]))]))])

>>> result['foo']

OrderedDict([(u'bar', OrderedDict([(u'type', [OrderedDict([(u'@foobar', u'1')]), OrderedDict([(u'@foobar', u'2')])])]))])

>>> result['foo']['bar']

OrderedDict([(u'type', [OrderedDict([(u'@foobar', u'1')]), OrderedDict([(u'@foobar', u'2')])])])

如果你使用python-benedict，就不需要使用lib特定的API。只需从XML初始化一个新实例并轻松管理它，因为它是dict子类。

安装很简单:pip install python-benedict

from benedict import benedict as bdict

# data-source can be an url, a filepath or data-string (as in this example)
data_source = """
<foo>
   <bar>
      <type foobar="1"/>
      <type foobar="2"/>
   </bar>
</foo>"""

data = bdict.from_xml(data_source)
t_list = data['foo.bar'] # yes, keypath supported
for t in t_list:
   print(t['@foobar'])

它支持并规范化多种格式的I/O操作:Base64, CSV, JSON, TOML, XML, YAML和查询字符串。

它在GitHub上经过了很好的测试和开源。披露:我是作者。

#If the xml is in the form of a string as shown below then
from lxml  import etree, objectify
'''sample xml as a string with a name space {http://xmlns.abc.com}'''
message =b'<?xml version="1.0" encoding="UTF-8"?>\r\n<pa:Process xmlns:pa="http://xmlns.abc.com">\r\n\t<pa:firsttag>SAMPLE</pa:firsttag></pa:Process>\r\n'  # this is a sample xml which is a string


print('************message coversion and parsing starts*************')

message=message.decode('utf-8') 
message=message.replace('<?xml version="1.0" encoding="UTF-8"?>\r\n','') #replace is used to remove unwanted strings from the 'message'
message=message.replace('pa:Process>\r\n','pa:Process>')
print (message)

print ('******Parsing starts*************')
parser = etree.XMLParser(remove_blank_text=True) #the name space is removed here
root = etree.fromstring(message, parser) #parsing of xml happens here
print ('******Parsing completed************')


dict={}
for child in root: # parsed xml is iterated using a for loop and values are stored in a dictionary
    print(child.tag,child.text)
    print('****Derving from xml tree*****')
    if child.tag =="{http://xmlns.abc.com}firsttag":
        dict["FIRST_TAG"]=child.text
        print(dict)


### output
'''************message coversion and parsing starts*************
<pa:Process xmlns:pa="http://xmlns.abc.com">

    <pa:firsttag>SAMPLE</pa:firsttag></pa:Process>
******Parsing starts*************
******Parsing completed************
{http://xmlns.abc.com}firsttag SAMPLE
****Derving from xml tree*****
{'FIRST_TAG': 'SAMPLE'}'''