学习一下python，这里对python的基础知识做一个整理。似等了一百年忽而明白，即使再见面，成熟地表演，不如不见。

python的一些应用

一、类似于java中的MessageFormat用法

word = "{0} love {1}"
wordList = (‘huhx‘, ‘linux‘)
print(word.format(*wordList))
print(word.format(‘huhx‘, ‘linux‘))

str_word = "{name} love {lover}"
wordMap = dict(name=‘huhx‘, lover=‘linux‘)
print(str_word.format(name=‘huhx‘, lover=‘linux‘))
print(str_word.format(**wordMap))
print(str_word.format_map(wordMap))

打印结果都是：huhx love linux

二、关于正则中贪心匹配的理解

import re
data = ‘Thu Feb 15 17:46:04 2007::[email protected]::1171590364-6-8‘
print(re.search(‘\d+-\d+-\d+‘, data).group()) # 1171590364-6-8
print(re.match(‘.+\d+-\d+-\d+‘, data).group()) # Thu Feb 15 17:46:04 2007::[email protected]::1171590364-6-8
print(re.match(‘.+(\d+-\d+-\d+)‘, data).group(1)) # 4-6-8
print(re.match(‘.+?(\d+-\d+-\d+)‘, data).group(1)) # 1171590364-6-8

三、python中简单的json请求

import http.client
import json

conn = http.client.HTTPConnection("hostname")
data = {
    ‘TellerId‘: ‘***‘,
    ‘Password‘: ‘***‘
}
payload = json.dumps(data)
headers = {
    ‘content-type‘: "application/json"
}
conn.request("POST", "/mweb/login.do", payload, headers)
res = conn.getresponse()
data = res.read()

print(data.decode("utf-8"))

四、python中简单的mysql连接

首先可以通过：pip install pymysql安装pymysql。

import pymysql

db = pymysql.connect("localhost","root","pass","database", charset=‘utf8‘)
cur = db.cursor()
cur.execute(‘select * from puser‘)

for i in cur.fetchall():
    print(str(i))
db.close()

五、python中使用sftp连接的简单使用

首先可以通过：pip install paramiko安装sftp的支持

import paramiko

host = ‘hostname‘
port = 22
user = ‘root‘
passwd = ‘password‘
# 创建SSH对象
ssh = paramiko.SSHClient()
# 允许连接不在know_hosts文件中的主机
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
# 连接服务器
ssh.connect(hostname=host, port=port, username=user, password=passwd)
# 执行命令
stdin, stdout, stderr = ssh.exec_command(‘ls -al‘)
# 获取命令结果
result = stdout.read()
print(result)
# 关闭连接
ssh.close()

六、python简单连接操作redis

首先启动redis服务，然后下载python的redis包：pip install redis。

import redis
r = redis.Redis(host=‘127.0.0.1‘,port=6379)
r.set(‘name‘, ‘linux‘)
print(r.get(‘name‘)) # linux

七、python简单的dom对xml的解析

from xml.dom.minidom import parse
import xml.dom.minidom

DOMTree = xml.dom.minidom.parse("huhx.xml")
collection = DOMTree.documentElement
persons = collection.getElementsByTagName(‘person‘)

for person in persons:
    if person.hasAttribute(‘name‘):
        print(‘my name is %s: ‘ % person.getAttribute(‘name‘))
    age = person.getElementsByTagName(‘age‘)[0].childNodes[0].data
    address = person.getElementsByTagName(‘address‘)[0].childNodes[0].data
    print(‘age = %d, address = %s.‘ % (int(age), address))

测试的huhx.xml文件如下：

<persons>
    <person name="huhx">
        <age>12</age>
        <address>wuhan</address>
    </person>
    <person name="linux">
        <age>1</age>
        <address>hubai</address>
    </person>
</persons>

运行的结果如下：

my name is huhx:
age = 12, address = wuhan.
my name is linux:
age = 1, address = hubai.

八、python中csv文件的读写

　　csv文件可以在excel表中建立数据，最后保存的时候存为csv格式的文件。

• 先看一个读取csv文件的内容，测试的huhx.csv文件内容如下：

import csv

csvFile = open(‘huhx.csv‘, ‘r‘)
reader = csv.reader(csvFile)

for item in reader:
    for subItem in item:
        print(subItem, end=" ")
    print()

运行的结果如下：

姓名 年龄 地址
huhx 23 china
linux 24 hubai
liuling 21 wuhan 

• python写入内容到csv文件

import csv

fileHeader = [‘username‘, ‘age‘, ‘address‘]
data1 = [‘huhx‘, 342, ‘hubai‘]
data2 = [‘linux‘, 56, ‘wuhan‘]
data3 = [‘tomhu‘, 44, ‘china‘]

csvFile = open(‘huhx.csv‘, ‘a‘)
writer = csv.writer(csvFile)
# writer.writerow(fileHeader)
# writer.writerow(data1)
# writer.writerow(data2)
# writer.writerow(data3)
writer.writerows([fileHeader, data1, data2, data3])
csvFile.close()

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