python模块（3）

1.xml：实现不同语言或程序之间进行数据交换的协议

<data>
    <country name="Liechtenstein">
        <rank updated="yes">2</rank>
        <year>2008</year>
        <gdppc>141100</gdppc>
        <neighbor name="Austria" direction="E"/>
        <neighbor name="Switzerland" direction="W"/>
    </country>
    <country name="Singapore">
        <rank updated="yes">5</rank>
        <year>2011</year>
        <gdppc>59900</gdppc>
        <neighbor name="Malaysia" direction="N"/>
    </country>
    <country name="Panama">
        <rank updated="yes">69</rank>
        <year>2011</year>
        <gdppc>13600</gdppc>
        <neighbor name="Costa Rica" direction="W"/>
        <neighbor name="Colombia" direction="E"/>
    </country>
</data>

遍历、修改、删除结点

 import xml.etree.ElementTree as ET

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

 # # 遍历xml文档
 # for child in root:
 #     print(child.tag, child.attrib)
 #     for i in child:
 #         print(i.tag, i.text)
 #
 # # 只遍历year 节点
 # for node in root.iter('year'):
 #     print(node.tag, node.text)

 # 修改node
 # for node in root.iter('year'):
 #     new_year=int(node.text)+1
 #     node.text=str(new_year)
 #     node.set('update','yes')
 #
 # tree.write('xml_test.xml')

 # 删除node
 for country in root.findall('country'):
     rank = int(country.find('rank').text)
     if rank>50:
         root.remove(country)

 tree.write('re_xml.xml')

创建

 import xml.etree.ElementTree as ET

 new_xml = ET.Element("namelist")

 person1= ET.SubElement(new_xml, "person1", attrib={"enrolled": "yes"})
 name = ET.SubElement(person1, "name")
 age = ET.SubElement(person1, "age", attrib={"checked": "no"})
 sex = ET.SubElement(person1, "sex")
 name.text = 'Alex'
 age.text = ''
 sex.text = 'man'

 person2 = ET.SubElement(new_xml, "person2", attrib={"enrolled": "no"})
 name = ET.SubElement(person2, "name")
 age = ET.SubElement(person2, "age")
 sex = ET.SubElement(person2, "sex")
 name.text = 'Bob'
 age.text = ''
 sex.text = 'man'

 et = ET.ElementTree(new_xml)  # 生成文档对象
 et.write("xml_create.xml", encoding="utf-8", xml_declaration=True)

 ET.dump(new_xml)  # 打印生成的格式

2.configparser:用于生成和修改常见配置文档

生成

 import configparser

 #创建configparse对象
 config = configparser.ConfigParser()
 #每个section都是一个字典
 config["DEFAULT"] = {'ServerAliveInterval': '',
                      'Compression': 'yes',
                      'CompressionLevel': ''}

 config['bitbucket.org'] = {}
 config['bitbucket.org']['User'] = 'hg'

 config['topsecret.server.com'] = {}
 topsecret = config['topsecret.server.com']
 topsecret['Host Port'] = ''
 topsecret['ForwardX11'] = 'no'

 config['DEFAULT']['ForwardX11'] = 'yes'
 with open('ha1.ini', 'w') as f:
     config.write(f)

读取

 import configparser
 #配置文件的读取与更改

 #创建configparse对象
 conf=configparser.ConfigParser()

 conf.read('ha1.ini')
 # print(conf.sections())
 # print(conf.defaults())
 print(conf['bitbucket.org']['user'])

 conf.remove_section('bitbucket.org')

 with open('conf.ini','w') as f:
     conf.write(f)

3.hashlib

import hashlib
# 加密的消息要以bytes类型传入相应的对象中

#生成md5对象
m = hashlib.md5()
#调用对象的update方法
m.update('Hello'.encode(encoding='utf-8'))  #str的encode方法，等价于转为bytes类型
print(m.hexdigest())
m.update(b"It's me")
print(m.hexdigest())  #第二次生成的是所有内容的密文

# 生成sha512对象
s1=hashlib.sha256()
s1.update('Hello这是一个测试'.encode(encoding='utf-8'))
print(s1.hexdigest())

4.hmac

import hmac
#对key和msg进行处理后再加密，安全性更高
#无论是密钥key，还是明文msg，一定要以bytes类型传入
m=hmac.new('family_861'.encode(encoding='utf-8'),'我要测试'.encode(encoding='utf-8'))  #key,msg都转换成bytes类型
print(m.digest())
print(m.hexdigest())