1、实现文件读写的文件ltz_schedule_times.py
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#! /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)
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2.1、不加锁对文件进行多线程读写。
file_lock.py
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#! /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()
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得到结果：
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0
write schedule_times start!
write schedule_times finish!
tmp: tmp: tmp: tmp: [[[['1''1''1''1']]]]
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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!
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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
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#! /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()
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结果：
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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!
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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服务器之家。
原文链接：https://blog.csdn.net/will130/article/details/50599577