常用python編程模板匯總

更新時(shí)間：2016年02月12日 18:30:48 作者：xingjiarong

這篇文章主要為大家詳細(xì)介紹了常用python編程模板，總結(jié)了Python編程常用模板，感興趣的朋友可以參考一下

在我們編程時(shí)，有一些代碼是固定的，例如Socket連接的代碼，讀取文件內(nèi)容的代碼，一般情況下我都是到網(wǎng)上搜一下然后直接粘貼下來(lái)改一改，當(dāng)然如果你能自己記住所有的代碼那更厲害，但是自己寫(xiě)畢竟不如粘貼來(lái)的快，而且自己寫(xiě)的代碼還要測(cè)試，而一段經(jīng)過(guò)測(cè)試的代碼則可以多次使用，所以這里我就自己總結(jié)了一下python中常用的編程模板，如果還有哪些漏掉了請(qǐng)大家及時(shí)補(bǔ)充哈。

一、讀寫(xiě)文件

1、讀文件

（1）、一次性讀取全部?jī)?nèi)容

filepath='D:/data.txt' #文件路徑

with open(filepath, 'r') as f:
  print f.read()

（2）讀取固定字節(jié)大小

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

filepath='D:/data.txt' #文件路徑

f = open(filepath, 'r')
content=""
try:
  while True:
    chunk = f.read(8)
    if not chunk:
      break
    content+=chunk
finally:
  f.close()
  print content

（3）每次讀取一行

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

filepath='D:/data.txt' #文件路徑

f = open(filepath, "r")
content=""
try:
  while True:
    line = f.readline()
    if not line:
      break
    content+=line
finally:
  f.close()
  print content

（4）一次讀取所有的行

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

filepath='D:/data.txt' #文件路徑

with open(filepath, "r") as f:
  txt_list = f.readlines()

for i in txt_list:
  print i,

2、寫(xiě)文件

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

filepath='D:/data1.txt' #文件路徑

with open(filepath, "w") as f: #w會(huì)覆蓋原來(lái)的文件，a會(huì)在文件末尾追加
  f.write('1234')

二、連接Mysql數(shù)據(jù)庫(kù)

1、連接

#!/usr/bin/python
# -*- coding: UTF-8 -*-

import MySQLdb

DB_URL='localhost'
USER_NAME='root'
PASSWD='1234'
DB_NAME='test'

# 打開(kāi)數(shù)據(jù)庫(kù)連接
db = MySQLdb.connect(DB_URL,USER_NAME,PASSWD,DB_NAME)

# 使用cursor()方法獲取操作游標(biāo) 
cursor = db.cursor()

# 使用execute方法執(zhí)行SQL語(yǔ)句
cursor.execute("SELECT VERSION()")

# 使用 fetchone() 方法獲取一條數(shù)據(jù)庫(kù)。
data = cursor.fetchone()

print "Database version : %s " % data

# 關(guān)閉數(shù)據(jù)庫(kù)連接
db.close()

2、創(chuàng)建表

#!/usr/bin/python
# -*- coding: UTF-8 -*-

import MySQLdb

# 打開(kāi)數(shù)據(jù)庫(kù)連接
db = MySQLdb.connect("localhost","testuser","test123","TESTDB" )

# 使用cursor()方法獲取操作游標(biāo) 
cursor = db.cursor()

# 如果數(shù)據(jù)表已經(jīng)存在使用 execute() 方法刪除表。
cursor.execute("DROP TABLE IF EXISTS EMPLOYEE")

# 創(chuàng)建數(shù)據(jù)表SQL語(yǔ)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)

# 關(guān)閉數(shù)據(jù)庫(kù)連接
db.close()

3、插入

#!/usr/bin/python
# -*- coding: UTF-8 -*-

import MySQLdb

# 打開(kāi)數(shù)據(jù)庫(kù)連接
db = MySQLdb.connect("localhost","testuser","test123","TESTDB" )

# 使用cursor()方法獲取操作游標(biāo) 
cursor = db.cursor()

# SQL 插入語(yǔ)句
sql = """INSERT INTO EMPLOYEE(FIRST_NAME,
     LAST_NAME, AGE, SEX, INCOME)
     VALUES ('Mac', 'Mohan', 20, 'M', 2000)"""
try:
  # 執(zhí)行sql語(yǔ)句
  cursor.execute(sql)
  # 提交到數(shù)據(jù)庫(kù)執(zhí)行
  db.commit()
except:
  # Rollback in case there is any error
  db.rollback()

# 關(guān)閉數(shù)據(jù)庫(kù)連接
db.close()

4、查詢

#!/usr/bin/python
# -*- coding: UTF-8 -*-

import MySQLdb

# 打開(kāi)數(shù)據(jù)庫(kù)連接
db = MySQLdb.connect("localhost","testuser","test123","TESTDB" )

# 使用cursor()方法獲取操作游標(biāo) 
cursor = db.cursor()

# SQL 查詢語(yǔ)句
sql = "SELECT * FROM EMPLOYEE \
    WHERE INCOME > '%d'" % (1000)
try:
  # 執(zhí)行SQL語(yǔ)句
  cursor.execute(sql)
  # 獲取所有記錄列表
  results = cursor.fetchall()
  for row in results:
   fname = row[0]
   lname = row[1]
   age = row[2]
   sex = row[3]
   income = row[4]
   # 打印結(jié)果
   print "fname=%s,lname=%s,age=%d,sex=%s,income=%d" % \
       (fname, lname, age, sex, income )
except:
  print "Error: unable to fecth data"

# 關(guān)閉數(shù)據(jù)庫(kù)連接
db.close()

5、更新

#!/usr/bin/python
# -*- coding: UTF-8 -*-

import MySQLdb

# 打開(kāi)數(shù)據(jù)庫(kù)連接
db = MySQLdb.connect("localhost","testuser","test123","TESTDB" )

# 使用cursor()方法獲取操作游標(biāo) 
cursor = db.cursor()

# SQL 更新語(yǔ)句
sql = "UPDATE EMPLOYEE SET AGE = AGE + 1
             WHERE SEX = '%c'" % ('M')
try:
  # 執(zhí)行SQL語(yǔ)句
  cursor.execute(sql)
  # 提交到數(shù)據(jù)庫(kù)執(zhí)行
  db.commit()
except:
  # 發(fā)生錯(cuò)誤時(shí)回滾
  db.rollback()

# 關(guān)閉數(shù)據(jù)庫(kù)連接
db.close()

三、Socket

1、服務(wù)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、客戶端

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、多線程

import time, threading

# 新線程執(zhí)行的代碼:
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

還請(qǐng)大家積極補(bǔ)充！

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