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

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

# -*- 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+=chunk

finally:

f.close()

print content

（3）每次读取一行

# -*- 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+=line

finally:

f.close()

print content

（4）一次读取所有的行

# -*- 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

# -*- 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

#!/usr/bin/python

# -*- coding: UTF-8 -*-

import MySQLdb

DB_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

#!/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()

3、插入

#!/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

#!/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()

5、更新

#!/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

from socket import *

from time import ctime

HOST = ''

PORT = 21568

BUFSIZ = 1024

ADDR = (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() 

break

tcpSerSock.close()

2、客户端

from socket import *

HOST = 'localhost'

PORT = 21568

BUFSIZ = 1024

ADDR = (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 data

except:

tcpCliSock.close() 

四、多线程

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().name

print 'thread %s is running...' % threading.current_thread().name

t = 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！