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Python对XML文件实现增删改查操作

时间:2022-11-11 09:55:51

这篇文章主要为大家详细介绍了Python对XML文件进行实现增删改查操作的方法,文中的示例代码讲解详细,具有一定的借鉴价值,感兴趣的可以了解一下!

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PYTHON 操作 XML

读取XML文件

关于XML的介绍

<data> 与 </data> 是一对标签的开始与结束

<property ... /> 也是一个正确的标签,以 /> 结尾,是在标签没有嵌套内容时的简写形式

name=“cat”,name是<data>标签的一个属性,cat是name属性的值

description here ...是<data>标签的内容,这里是一段文本。当然也可以是xml的嵌套

<data name="cat" num="10"> description here ... </data>

<property value="node" />

<country name="china">
	<province name="beijing">
		<school name="the sunshine school" />
	</province>
</country>

准备一个demo.xml文件

<data>
<teacher name="Albert">
<birthday>1980</birthday>
<gender>male</gender>
<subject>Math</subject>
</teacher>

<student name="Becky">
<birthday>2000</birthday>
<gender>female</gender>
<hobbies>
<hobby>skating</hobby>
<hobby>rocks</hobby>
</hobbies>
<exam absence="no">
<math>90</math>
<english>90</english>
<music>95</music>
</exam>

</student>
<student name="Cindy">
<birthday>2001</birthday>
<gender>female</gender>
<hobbies>
<hobby>reading</hobby>
<hobby>guitar</hobby>
</hobbies>
<exam absence="yes">
</exam>
</student>

<student name="Duke">
<birthday>2000</birthday>
<gender>male</gender>
<hobbies>
<hobby>football</hobby>
<hobby>surfing</hobby>
</hobbies>
<exam absence="no">
<math>100</math>
<english>80</english>
<music>92</music>
</exam>
</student>

</data>

读取xml文件内容

# Read the .xml file
tree = ET.parse("demo.xml")
root = tree.getroot()
print(root)

结果

<Element 'data' at 0x102d80cf8>

遍历XML元素

for ... in ... 可以遍历当前元素的所有直接子节点

for n in root:
# items() returns all <key, value> pairs of the tag
print(n, n.tag , n.attrib, n.items())

结果

(<Element 'teacher' at 0x1048b9e48>, 'teacher', {'name': 'Albert'}, [('name', 'Albert')])

(<Element 'student' at 0x1048bf0f0>, 'student', {'name': 'Becky'}, [('name', 'Becky')])

(<Element 'student' at 0x1048bf3c8>, 'student', {'name': 'Cindy'}, [('name', 'Cindy')])

(<Element 'student' at 0x1048bf5f8>, 'student', {'name': 'Duke'}, [('name', 'Duke')])

想要迭代遍历当前元素的所有子节点(包括子孙节点)

for n in root.iter():
print(n, n.tag)

结果

(<Element 'data' at 0x1052f0cf8>, 'data')

(<Element 'teacher' at 0x1052f0e48>, 'teacher')

(<Element 'birthday' at 0x1052f0d30>, 'birthday')

(<Element 'gender' at 0x1052f6080>, 'gender')

(<Element 'subject' at 0x1052f60b8>, 'subject')

(<Element 'student' at 0x1052f60f0>, 'student')

(<Element 'birthday' at 0x1052f6048>, 'birthday')

(<Element 'gender' at 0x1052f6128>, 'gender')

(<Element 'hobbies' at 0x1052f6198>, 'hobbies')

(<Element 'hobby' at 0x1052f6208>, 'hobby')

(<Element 'hobby' at 0x1052f6240>, 'hobby')

(<Element 'exam' at 0x1052f62b0>, 'exam')

(<Element 'math' at 0x1052f6320>, 'math')

(<Element 'english' at 0x1052f6390>, 'english')

(<Element 'music' at 0x1052f6400>, 'music')

(<Element 'student' at 0x1052f63c8>, 'student')

(<Element 'birthday' at 0x1052f6438>, 'birthday')

(<Element 'gender' at 0x1052f6470>, 'gender')

(<Element 'hobbies' at 0x1052f64a8>, 'hobbies')

(<Element 'hobby' at 0x1052f6518>, 'hobby')

(<Element 'hobby' at 0x1052f6588>, 'hobby')

(<Element 'exam' at 0x1052f65c0>, 'exam')

(<Element 'student' at 0x1052f65f8>, 'student')

(<Element 'birthday' at 0x1052f6630>, 'birthday')

(<Element 'gender' at 0x1052f6668>, 'gender')

(<Element 'hobbies' at 0x1052f66a0>, 'hobbies')

(<Element 'hobby' at 0x1052f6710>, 'hobby')

(<Element 'hobby' at 0x1052f6780>, 'hobby')

(<Element 'exam' at 0x1052f67b8>, 'exam')

(<Element 'math' at 0x1052f6828>, 'math')

(<Element 'english' at 0x1052f6898>, 'english')

(<Element 'music' at 0x1052f6908>, 'music')

想要选择性地迭代直接子节点

for n in root.iter('teacher'):
print(n, n.tag)
(<Element 'teacher' at 0x100f29e48>, 'teacher')

查找XML元素

find与findall查找xml元素

# find the first element
print(root.find('student'))
# find all  elements
print(root.findall('student'))
<Element 'student' at 0x1034300f0>

[<Element 'student' at 0x1034300f0>, <Element 'student' at 0x1034303c8>, <Element 'student' at 0x1034305f8>]

demo

for n in root:
if n.tag == 'student' and n.get('name') == 'Becky':
exam_node = n.find('exam')
for subject in exam_node:
print(subject.tag + " " + subject.text)

结果

math 90

english 90

music 95

添加XML元素

p = ET.Element(tag_name)

demo

for n in root:
if n.tag == 'student' and n.get('name') == 'Cindy':
exam_node = n.find('exam')
exam_node.set("absence", "no")
for subject in ['math', 'music']:
p = ET.Element(subject)
p.text = '90'
exam_node.append(p)

if os.path.exists('new.xml'):
os.remove('new.xml')
tree.write('new.xml', encoding='utf-8', xml_declaration=True)

结果

    <student name="Cindy">

        <birthday>2001</birthday>

        <gender>female</gender>

        <hobbies>

            <hobby>reading</hobby>

            <hobby>guitar</hobby>

        </hobbies>

        <exam absence="no">

        <math>90</math><music>90</music></exam>

    </student>

修改XML元素

demo

for n in root:
if n.tag == 'student' and n.get('name') == 'Cindy':
exam_node = n.find('exam')
exam_node.set("absence", "no")
exam_node.set("date", "2022-11-11")
for subject in ['math', 'music']:
p = ET.Element(subject)
p.text = '90'
exam_node.append(p)

hobbies_node = n.find('hobbies').findall("hobby")
hobbies_node[0].text = 'piano'
p = ET.Element("hobby")
p.set("old_hobby", 'yes')
p.text = 'reading'
n.find('hobbies').remove(hobbies_node[1])
n.find('hobbies').append(p)

结果

    <student name="Cindy">

        <birthday>2001</birthday>

        <gender>female</gender>

        <hobbies>

            <hobby>piano</hobby>

            <hobby old_hobby="yes">reading</hobby></hobbies>

        <exam absence="no" date="2022-11-11">

        <math>90</math><music>90</music></exam>

    </student>

标签: PythonXML