在我们编程时，有一些代码是固定的，例如Socket连接的代码，读取文件内容的代码，一般情况下我都是到网上搜一下然后直接粘贴下来改一改，当然如果你能自己记住所有的代码那更厉害，但是自己写毕竟不如粘贴来的快，而且自己写的代码还要测试，而一段经过测试的代码则可以多次使用，所以这里我就自己总结了一下python中常用的编程模板，如果还有哪些漏掉了请大家及时补充哈。
一、读写文件
1、读文件
（1）、一次性读取全部内容
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filepath='D:/data.txt' #文件路径with open(filepath, 'r') as f: print f.read() |
（2）读取固定字节大小
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# -*- coding: UTF-8 -*-filepath='D:/data.txt' #文件路径f = open(filepath, 'r')content=""try: while True: chunk = f.read(8) if not chunk: break content+=chunkfinally: f.close() print content |
（3）每次读取一行
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# -*- coding: UTF-8 -*-filepath='D:/data.txt' #文件路径f = open(filepath, "r")content=""try: while True: line = f.readline() if not line: break content+=linefinally: f.close() print content |
（4）一次读取所有的行
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# -*- coding: UTF-8 -*-filepath='D:/data.txt' #文件路径with open(filepath, "r") as f: txt_list = f.readlines()for i in txt_list: print i, |
2、写文件
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# -*- coding: UTF-8 -*-filepath='D:/data1.txt' #文件路径with open(filepath, "w") as f: #w会覆盖原来的文件，a会在文件末尾追加 f.write('1234') |
二、连接Mysql数据库
1、连接
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#!/usr/bin/python# -*- coding: UTF-8 -*-import MySQLdbDB_URL='localhost'USER_NAME='root'PASSWD='1234'DB_NAME='test'# 打开数据库连接db = MySQLdb.connect(DB_URL,USER_NAME,PASSWD,DB_NAME)# 使用cursor()方法获取操作游标 cursor = db.cursor()# 使用execute方法执行SQL语句cursor.execute("SELECT VERSION()")# 使用 fetchone() 方法获取一条数据库。data = cursor.fetchone()print "Database version : %s " % data# 关闭数据库连接db.close() |
2、创建表
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<p>#!/usr/bin/python# -*- coding: UTF-8 -*-import MySQLdb# 打开数据库连接db = MySQLdb.connect("localhost","testuser","test123","TESTDB" )# 使用cursor()方法获取操作游标 cursor = db.cursor()# 如果数据表已经存在使用 execute() 方法删除表。cursor.execute("DROP TABLE IF EXISTS EMPLOYEE")# 创建数据表SQL语句sql = """CREATE TABLE EMPLOYEE ( FIRST_NAME CHAR(20) NOT NULL, LAST_NAME CHAR(20), AGE INT, SEX CHAR(1), INCOME FLOAT )"""cursor.execute(sql)# 关闭数据库连接db.close()</p> |
3、插入
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#!/usr/bin/python# -*- coding: UTF-8 -*-import MySQLdb# 打开数据库连接db = MySQLdb.connect("localhost","testuser","test123","TESTDB" )# 使用cursor()方法获取操作游标 cursor = db.cursor()# SQL 插入语句sql = """INSERT INTO EMPLOYEE(FIRST_NAME, LAST_NAME, AGE, SEX, INCOME) VALUES ('Mac', 'Mohan', 20, 'M', 2000)"""try: # 执行sql语句 cursor.execute(sql) # 提交到数据库执行 db.commit()except: # Rollback in case there is any error db.rollback()# 关闭数据库连接db.close() |
4、查询
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<p>#!/usr/bin/python# -*- coding: UTF-8 -*-import MySQLdb# 打开数据库连接db = MySQLdb.connect("localhost","testuser","test123","TESTDB" )# 使用cursor()方法获取操作游标 cursor = db.cursor()# SQL 查询语句sql = "SELECT * FROM EMPLOYEE \ WHERE INCOME > '%d'" % (1000)try: # 执行SQL语句 cursor.execute(sql) # 获取所有记录列表 results = cursor.fetchall() for row in results: fname = row[0] lname = row[1] age = row[2] sex = row[3] income = row[4] # 打印结果 print "fname=%s,lname=%s,age=%d,sex=%s,income=%d" % \ (fname, lname, age, sex, income )except: print "Error: unable to fecth data"# 关闭数据库连接db.close()</p> |
5、更新
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#!/usr/bin/python# -*- coding: UTF-8 -*-import MySQLdb# 打开数据库连接db = MySQLdb.connect("localhost","testuser","test123","TESTDB" )# 使用cursor()方法获取操作游标 cursor = db.cursor()# SQL 更新语句sql = "UPDATE EMPLOYEE SET AGE = AGE + 1 WHERE SEX = '%c'" % ('M')try: # 执行SQL语句 cursor.execute(sql) # 提交到数据库执行 db.commit()except: # 发生错误时回滚 db.rollback()# 关闭数据库连接db.close() |
三、Socket
1、服务器
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from socket import *from time import ctimeHOST = ''PORT = 21568BUFSIZ = 1024ADDR = (HOST, PORT)tcpSerSock = socket(AF_INET, SOCK_STREAM)tcpSerSock.bind(ADDR)tcpSerSock.listen(5)while True: print 'waiting for connection...' tcpCliSock, addr = tcpSerSock.accept() print '...connected from:', addr while True: try: data = tcpCliSock.recv(BUFSIZ) print '<', data tcpCliSock.send('[%s] %s' % (ctime(), data)) except: print 'disconnect from:', addr tcpCliSock.close() breaktcpSerSock.close() |
2、客户端
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from socket import *HOST = 'localhost'PORT = 21568BUFSIZ = 1024ADDR = (HOST, PORT)tcpCliSock = socket(AF_INET, SOCK_STREAM)tcpCliSock.connect(ADDR) try: while True: data = raw_input('>') if data == 'close': break if not data: continue tcpCliSock.send(data) data = tcpCliSock.recv(BUFSIZ) print dataexcept: tcpCliSock.close() |
四、多线程
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import time, threading# 新线程执行的代码:def loop(): print 'thread %s is running...' % threading.current_thread().name n = 0 while n < 5: n = n + 1 print 'thread %s >>> %s' % (threading.current_thread().name, n) time.sleep(1) print 'thread %s ended.' % threading.current_thread().nameprint 'thread %s is running...' % threading.current_thread().namet = threading.Thread(target=loop, name='LoopThread')t.start()t.join()print 'thread %s ended.' % threading.current_thread().name |
还请大家积极补充！
