我在XML中有很多行,我试图获得一个特定节点属性的实例。

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

我如何访问属性foobar的值?在这个例子中,我想要“1”和“2”。


当前回答

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')])])])

其他回答

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

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')])])])

如果源文件是一个xml文件,就像这个示例一样

<pa:Process xmlns:pa="http://sssss">
        <pa:firsttag>SAMPLE</pa:firsttag>
    </pa:Process>

您可以尝试下面的代码

from lxml import etree, objectify
metadata = 'C:\\Users\\PROCS.xml' # this is sample xml file the contents are shown above
parser = etree.XMLParser(remove_blank_text=True) # this line removes the  name space from the xml in this sample the name space is --> http://sssss
tree = etree.parse(metadata, parser) # this line parses the xml file which is PROCS.xml
root = tree.getroot() # we get the root of xml which is process and iterate using a for loop
for elem in root.getiterator():
    if not hasattr(elem.tag, 'find'): continue  # (1)
    i = elem.tag.find('}')
    if i >= 0:
        elem.tag = elem.tag[i+1:]

dict={}  # a python dictionary is declared
for elem in tree.iter(): #iterating through the xml tree using a for loop
    if elem.tag =="firsttag": # if the tag name matches the name that is equated then the text in the tag is stored into the dictionary
        dict["FIRST_TAG"]=str(elem.text)
        print(dict)

输出将是

{'FIRST_TAG': 'SAMPLE'}

如果您不想使用任何外部库或第三方工具,请尝试下面的代码。

这将把xml解析成python字典 这也将解析xml属性 这也将解析空标签,如<tag/>和只有属性的标签,如<tag var=val/>

Code

import re

def getdict(content):
    res=re.findall("<(?P<var>\S*)(?P<attr>[^/>]*)(?:(?:>(?P<val>.*?)</(?P=var)>)|(?:/>))",content)
    if len(res)>=1:
        attreg="(?P<avr>\S+?)(?:(?:=(?P<quote>['\"])(?P<avl>.*?)(?P=quote))|(?:=(?P<avl1>.*?)(?:\s|$))|(?P<avl2>[\s]+)|$)"
        if len(res)>1:
            return [{i[0]:[{"@attributes":[{j[0]:(j[2] or j[3] or j[4])} for j in re.findall(attreg,i[1].strip())]},{"$values":getdict(i[2])}]} for i in res]
        else:
            return {res[0]:[{"@attributes":[{j[0]:(j[2] or j[3] or j[4])} for j in re.findall(attreg,res[1].strip())]},{"$values":getdict(res[2])}]}
    else:
        return content

with open("test.xml","r") as f:
    print(getdict(f.read().replace('\n','')))

样例输入

<details class="4b" count=1 boy>
    <name type="firstname">John</name>
    <age>13</age>
    <hobby>Coin collection</hobby>
    <hobby>Stamp collection</hobby>
    <address>
        <country>USA</country>
        <state>CA</state>
    </address>
</details>
<details empty="True"/>
<details/>
<details class="4a" count=2 girl>
    <name type="firstname">Samantha</name>
    <age>13</age>
    <hobby>Fishing</hobby>
    <hobby>Chess</hobby>
    <address current="no">
        <country>Australia</country>
        <state>NSW</state>
    </address>
</details>

输出(美化)

[
  {
    "details": [
      {
        "@attributes": [
          {
            "class": "4b"
          },
          {
            "count": "1"
          },
          {
            "boy": ""
          }
        ]
      },
      {
        "$values": [
          {
            "name": [
              {
                "@attributes": [
                  {
                    "type": "firstname"
                  }
                ]
              },
              {
                "$values": "John"
              }
            ]
          },
          {
            "age": [
              {
                "@attributes": []
              },
              {
                "$values": "13"
              }
            ]
          },
          {
            "hobby": [
              {
                "@attributes": []
              },
              {
                "$values": "Coin collection"
              }
            ]
          },
          {
            "hobby": [
              {
                "@attributes": []
              },
              {
                "$values": "Stamp collection"
              }
            ]
          },
          {
            "address": [
              {
                "@attributes": []
              },
              {
                "$values": [
                  {
                    "country": [
                      {
                        "@attributes": []
                      },
                      {
                        "$values": "USA"
                      }
                    ]
                  },
                  {
                    "state": [
                      {
                        "@attributes": []
                      },
                      {
                        "$values": "CA"
                      }
                    ]
                  }
                ]
              }
            ]
          }
        ]
      }
    ]
  },
  {
    "details": [
      {
        "@attributes": [
          {
            "empty": "True"
          }
        ]
      },
      {
        "$values": ""
      }
    ]
  },
  {
    "details": [
      {
        "@attributes": []
      },
      {
        "$values": ""
      }
    ]
  },
  {
    "details": [
      {
        "@attributes": [
          {
            "class": "4a"
          },
          {
            "count": "2"
          },
          {
            "girl": ""
          }
        ]
      },
      {
        "$values": [
          {
            "name": [
              {
                "@attributes": [
                  {
                    "type": "firstname"
                  }
                ]
              },
              {
                "$values": "Samantha"
              }
            ]
          },
          {
            "age": [
              {
                "@attributes": []
              },
              {
                "$values": "13"
              }
            ]
          },
          {
            "hobby": [
              {
                "@attributes": []
              },
              {
                "$values": "Fishing"
              }
            ]
          },
          {
            "hobby": [
              {
                "@attributes": []
              },
              {
                "$values": "Chess"
              }
            ]
          },
          {
            "address": [
              {
                "@attributes": [
                  {
                    "current": "no"
                  }
                ]
              },
              {
                "$values": [
                  {
                    "country": [
                      {
                        "@attributes": []
                      },
                      {
                        "$values": "Australia"
                      }
                    ]
                  },
                  {
                    "state": [
                      {
                        "@attributes": []
                      },
                      {
                        "$values": "NSW"
                      }
                    ]
                  }
                ]
              }
            ]
          }
        ]
      }
    ]
  }
]