1、实现文件读写的文件ltz_schedule_times.py

#! /usr/bin/env python

#coding=utf-8

import os

def ReadTimes():

res = []

if os.path.exists('schedule_times.txt'):

fp = open('schedule_times.txt', 'r')

else:

os.system('touch schedule_times.txt')

fp = open('schedule_times.txt', 'r')

try:

line = fp.read()

if line == None or len(line)==0:

fp.close()

return 0

tmp = line.split()

print 'tmp: ', tmp

schedule_times = int(tmp[-1])

finally:

fp.close()

#print schedule_times

return schedule_times

def WriteTimes(schedule_times):

if schedule_times <= 10:

fp = open('schedule_times.txt', 'a+')#10以内追加进去

else:

fp = open('schedule_times.txt', 'w')#10以外重新写入

schedule_times = 1

print 'write schedule_times start!'

try:

fp.write(str(schedule_times)+'\n')

finally:

fp.close()

print 'write schedule_times finish!'

if __name__ == '__main__':

schedule_times = ReadTimes()

#if schedule_times > 10:

# schedule_times = 0

print schedule_times

schedule_times = schedule_times + 1

WriteTimes(schedule_times)

2.1、不加锁对文件进行多线程读写。

file_lock.py

#! /usr/bin/env python

#coding=utf-8

from threading import Thread

import threading

import time

from ltz_schedule_times import *

#1、不加锁

def lock_test():

time.sleep(0.1)

schedule_times = ReadTimes()

print schedule_times

schedule_times = schedule_times + 1

WriteTimes(schedule_times)

if __name__ == '__main__':

for i in range(5):

Thread(target = lock_test, args=()).start()

得到结果：

0

write schedule_times start!

write schedule_times finish!

tmp: tmp: tmp: tmp: [[[['1''1''1''1']]]]

11

1

1

write schedule_times start!write schedule_times start!

write schedule_times start!write schedule_times start!

write schedule_times finish!

write schedule_times finish!

write schedule_times finish!write schedule_times finish!

文件写入结果：

以上结果可以看出，不加锁多线程读写文件会出现错误。

2.2、加锁对文件进行多线程读写。

file_lock.py

#! /usr/bin/env python

#coding=utf-8

from threading import Thread

import threading

import time

from ltz_schedule_times import *

#2、加锁

mu = threading.Lock() #1、创建一个锁

def lock_test():

#time.sleep(0.1)

if mu.acquire(True): #2、获取锁状态，一个线程有锁时，别的线程只能在外面等着

schedule_times = ReadTimes()

print schedule_times

schedule_times = schedule_times + 1

WriteTimes(schedule_times)

mu.release() #3、释放锁

if __name__ == '__main__':

for i in range(5):

Thread(target = lock_test, args=()).start()

结果：

0

write schedule_times start!

write schedule_times finish!

tmp: ['1']

1

write schedule_times start!

write schedule_times finish!

tmp: ['1', '2']

2

write schedule_times start!

write schedule_times finish!

tmp: ['1', '2', '3']

3

write schedule_times start!

write schedule_times finish!

tmp: ['1', '2', '3', '4']

4

write schedule_times start!

write schedule_times finish!

文件写入结果：

以上这篇Python多线程同步---文件读写控制方法就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持python博客。