python-configparser模块,xml.etree模块

操作键值对文件

 #文件db格式为
 [section]
 a = 1
 b = 2

 [section1]
 d = 3
 c = 4

 import configparser

 #获取所有节点
 config = configparser.ConfigParser()
 config.read('db')
 ret = config.sections()
 print(ret)

 >>>['section', 'section1']

 #获取指定节点下所有的键值对
 ret = config.items('section1')
 print('获取键值对：',ret)
 >>>获取键值对： [('d', ''), ('c', '')]

 #获取所有的键
 ret = config.options('section')
 print('获取节点下键名称：',ret)
 >>>获取节点下键名称： ['a', 'b']

 #获取节点下的指定key的值
 ret =config.get('section1','c')
 print(ret)
 >>>4

 #检查节点是否存在
 has_sec = config.has_section('section1')
 print(has_sec)
 >>>True

 #添加节点section2
 config.add_section('section2')
 config.write(open('db','w'))

 #db文件当前为
 [section]
 a = 1
 b = 2

 [section1]
 d = 3
 c = 4

 [section2]

 #删除节点section2
 config.remove_section('section2')
 config.write(open('db','w'))

 #当前db文件内容为
 [section]
 a = 1
 b = 2

 [section1]
 d = 3
 c = 4

 #检查删除设置指定组内的键值对是否存在
 has_opt = config.has_option('section1','c')
 print(has_opt)
 >>>True

 #删除
 config.remove_option('section1','c')
 config.write(open('db','w'))
 #当前db文件内容为
 [section]
 a = 1
 b = 2

 [section1]
 d = 3

 #设置更改指定值
 config.set('section1','d','')
 config.write(open('db','w'))
 #db内容
 [section]
 a = 1
 b = 2

 [section1]
 d = 123
 c = 4

 #oo.xml文件内容
 <data>
     <country name="Liechtenstein">
         <rank updated="yes">2</rank>
         <year>2023</year>
         <year>2027</year>
         <year>2027</year>
         <gdppc>141100</gdppc>
         <neighbor direction="E" name="Austria" />
         <neighbor direction="W" name="Switzerland" />
     </country>
 </data>

 from xml.etree import ElementTree as ET

 #打开xml文件加载到内存
 tree = ET.parse('oo.xml')
 #获取根节点
 root = tree.getroot()

 for child in root:
     print(child.tag,child.attrib)#child.tag,子节点标签名,子节点属性
     for gradechild in child:
         print(gradechild.tag,gradechild.text,gradechild.attrib)

 >>>country {'name': 'Liechtenstein'}
 >>>rank 2 {'updated': 'yes'}
 >>>year 2023 {}
 >>>gdppc 141100 {}
 >>>neighbor None {'direction': 'E', 'name': 'Austria'}
 >>>neighbor None {'direction': 'W', 'name': 'Switzerland'}

 #两种方法读取xml文件直接解析,tree对象是ElementTree对象
 tree = ET.parse('oo.xml')
 root = tree.getroot()

 #将xml已字符串格式获得,将字符串转化为element对象,无法进行写操作
 str_xml = open('oo.xml','r').read()
 root = ET.XML(str_xml)

 #循环所有的year节点
 for node in root.iter('year'):
     #将year节点中的内容自增一
     new_year = int (node.text) +1
     node.text = str(new_year)
     print(node.text)
 >>>2024
 >>>2027
 >>>2027
     #设置属性
     node.set('name','alex')
     node.set('age','')
     print(node.attrib)
 >>>{'age': '', 'name': 'alex'}
 >>>{'age': '', 'name': 'alex'}
 >>>{'age': '', 'name': 'alex'}
     #删除属性
     del node.attrib['name']
     print(node.attrib)
 >>>{'age': ''}
 >>>{'age': ''}
 >>>{'age': ''}
 #保存文件
 tree = ET.ElementTree(root)
 tree.write("newnew.xml", encoding='utf-8')

 #创建根节点
 root = ET.Element('family')

 #创建大儿子
 son1 = ET.Element('son',{'name':'儿子1'})
 #创建二儿子
 son2 = ET.Element('son',{'name':'儿子2'})

 #大儿子中创建两个孙子
 grandson1 = ET.Element('grandson',{'name':'孙子1'})
 grandson2 = ET.Element('grandson',{'name':'孙子2'})
 son1.append(grandson1)
 son2.append(grandson2)

 root.append(son1)
 root.append(son2)

 tree = ET.ElementTree(root)
 tree.write('ooo.xml',encoding = 'utf-8',short_empty_elements = False)
 #ooo.xml文件为
 <family><son name="儿子1"><grandson name="孙子1"></grandson></son><son name="儿子2"><grandson name="孙子2"></grandson></son></family>