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 = '33'
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 = '19'
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': '45',
                     'Compression': 'yes',
                     'CompressionLevel': '9'}

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

config['topsecret.server.com'] = {}
topsecret = config['topsecret.server.com']
topsecret['Host Port'] = '50022'
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())