这篇文章将为大家详细讲解有关怎么在Python中利用多线程同步实现文件读写控制,文章内容质量较高,因此小编分享给大家做个参考,希望大家阅读完这篇文章后对相关知识有一定的了解。
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:

python是什么意思
Python是一种跨平台的、具有解释性、编译性、互动性和面向对象的脚本语言,其最初的设计是用于编写自动化脚本,随着版本的不断更新和新功能的添加,常用于用于开发独立的项目和大型项目。
关于怎么在Python中利用多线程同步实现文件读写控制就分享到这里了,希望以上内容可以对大家有一定的帮助,可以学到更多知识。如果觉得文章不错,可以把它分享出去让更多的人看到。