python learning, day5: built-in module (management xml file)

Import module

import xml.etree.ElementTree as ET

Read parsing XML

Can be resolved from the string xml file
to create a new file xml

    <?xml version="1.0" encoding="UTF-8"?> <students> <student> <name>张三</name> <age>18</age> <score>89</score> </student> <student> <name>李四</name> <age>19</age> <score>81</score> </student> <student> <name>王五</name> <age>17</age> <score>92</score> </student> </students>

Xml file read from using getRoot () Gets the root, an Element object is obtained

tree = ET.parse('students.xml')
root = tree.getroot()

Read from the string variable, the Element object is returned

root = ET.fromstring(country_data_as_string)

Access XML

Each Element has the following properties

    #tag = element.text #访问Element标签
    #attrib = element.attrib #访问Element属性
    #text = element.text #访问Element文本

    for element in root.findall('student'): tag = element.tag #访问Element标签 attrib = element.attrib #访问Element属性 text = element.find('name').text #访问Element文本 print(tag, attrib, text) print(root[0][0].text) #子节点是嵌套的，我们可以通关索引访问特定的子节点

Finding Elements

Element provides a number of ways to help us to traverse of his child node

1、Element.iter()

    for student in root.iter('student'):
        print student[0].text out: 张三 李四 王五

2、Element.findall()

    for element in root.findall('student'):
        name = element.find('name').text
        age = element.find('age').text score = element.find('score').text print name,age,score out: 张三 18 89 李四 19 81 王五 17 92

Modify XML

ElementTree.write () will build the XML document written to the file.
Element.text = '' to directly change the contents of the field
Element.append (Element) add a child object objects for the current Elment
Element.remove (Element) Delete Element node
Element.set (key, value) add and modify attributes
ElementTree.write ( 'filename.xml') write (update) XMl file

Creating XML

ElementTree.Element () Construction of a node
ElementTree.SubElement (Element, tag) to build a child node

    a = ET.Element('a')  
    b = ET.SubElement(a, 'b')  
    c = ET.SubElement(a, 'c')  
    print ET.dump(a)  
    out:
    &lt;a>&lt;b />&lt;c />&lt;/a>

to sum up

Recently wrote things are needed output xml, so learning the use of XML and XML in the python. More can be seen official documentation.