常⽤python编程模板汇总
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:/' #⽂件路径
with open(filepath, 'r') as f:
ad()
（2）读取固定字节⼤⼩
# -*- coding: UTF-8 -*-
filepath='D:/' #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:/' #⽂件路径
f = open(filepath, "r")
content=""
hbase列族是什么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
inherited什么意思
# -*- coding: UTF-8 -*-
filepath='D:/' #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:/' #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 = t(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
# 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 = t("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。
# 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 )"""
# 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 = t("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:
shell脚本基本命令echo# 执⾏sql语句
# 提交到数据库执⾏
dbmit()
except:
# Rollback in case there is any error
# 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 = t("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
# 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 = t("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
# 提交到数据库执⾏
dbmit()
except:
# 发⽣错误时回滚
# 关闭数据库连接
db.close()
三、Socket
1、服务器
from socket import *
from time import ctime
HOST = ''
配置struts2PORT = 21568
BUFSIZ = 1024
ADDR = (HOST, PORT)
tcpSerSock = socket(AF_INET, SOCK_STREAM) tcpSerSock.bind(ADDR)
tcpSerSock.listen(5)
while True:
print 'waiting '
tcpCliSock, addr = tcpSerSock.accept()
print '...connected from:', addr
while True:
try:
python基础代码大全下载data = v(BUFSIZ)
print '<', data
tcpCliSock.send('[%s] %s' % (ctime(), data))    except:
qt checkbox样式
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) t(ADDR)
try:
while True:
data = raw_input('>')
if data == 'close':
break
if not data:
continue
tcpCliSock.send(data)
data = v(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 ' % 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 ' % 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！

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