python中的线程技术

#!/user/bin/env python
# @Time     :2018/7/7 11:42
# @Author   :PGIDYSQ
#@File      :DaemonTest.py
import threading,time
# 1.线程的简单使用
# class MyThread(threading.Thread):
#     def __init__(self,num,threadname):
#         threading.Thread.__init__(self,name=threadname)
#         self.num = num
#     def run(self):
#         time.sleep(self.num)
#         print(self.num)
#
# t1 = MyThread(1,'t1')
# t2 = MyThread(5,'t2')
#
# t2.daemon = True
# print(t1.daemon)
# print(t2.daemon)
#
# t1.start()
# t2.start()

#2.多线程使用，线程同步技术

# class MyThread2(threading.Thread):
#     def __init__(self):
#         threading.Thread.__init__(self)
#     #重写run方法
#     def run(self):
#         global x
#         #获取锁，
#         lock.acquire()#相当于同步语块
#         x = x+3
#         print(x)
#         #释放锁
#         lock.release()
#
# lock = threading.RLock()
# #存放多个线程列表
# t12 = []
# #创建线程
# for i in range(10):
#     #创建线程并添加到列表中
#     t = MyThread2()
#     t12.append(t)
# #多个线程互斥访问的变量
# x = 0
# #启动所有线程
# for i in t12:
#     i.start()
#3.使用Condition实现生产者与消费者关系
from random  import randint
from time import sleep
#自定义生产者线程类
class Producer(threading.Thread):
    def __init__(self,threadname):
        threading.Thread.__init__(self,name = threadname)
    def run(self):
        global x
        while True:
            con.acquire()
            if(len(x) == 10):
                con.wait()
                print('生产者等待中...')
            else:
                print('生产者:',end=' ')
                x.append(randint(1,1000))
                print('生产的数据：%s'%x)
                sleep(1)
                #唤醒等待条件的线程
                con.notify()
            #释放锁
            con.release()
#自定义消费者线程类
class Consumer(threading.Thread):
    def __init__(self,threadname):
        threading.Thread.__init__(self,name = threadname)
    def run(self):
        global x
        while True:
            #获取锁
            con.acquire()
            if not x:
                con.wait()
                print("消费者等待中...")
            else:
                print('消费的数据：%s'%x.pop(0))
                print('消费后剩余的数据：%s'%x)
                sleep(2)
                con.notify()
            con.release()

#创建Condition对象并测试
con = threading.Condition()
x = []
p = Producer("Producer")
c = Consumer("Consumer")

# p.start()
# c.start()
# p.join()
# c.join()
#4.还有Queue对象，Event对象使用...

#5.进程的使用
# from multiprocessing import Process
# import os
# from statistics import mean
#
# def f(name):
#     print(os.getppid())
#     print(name)
# if __name__ == '__main__':
#     pro1 = Process(target=f,args=('yao',))
#     pro1.start()
#     pro1.join()
#6.计算二维数组每行的平均值
# x =[list(range(10)),list(range(20,30)),list(range(40,50)),list(range(70,90))]
# from multiprocessing import Pool
# from statistics import mean
# def f(x):
#     return mean(x)#求平均值
# if __name__ == '__main__':
#     with Pool(5) as p:
#         print(p.map(f,x))

#7.使用管道实现进程间数据交换
# from multiprocessing import Process,Pipe
# def f(conn):
#     conn.send('hello world')
#     conn.close()
# if __name__ == "__main__":
#     parent_conn,child_conn = Pipe()#创建管道对象，并设置接收端与发送端
#     p = Process(target=f,args=(parent_conn,))#将管道的一方做为参数传递给子进程
#     p.start()
#     p.join()
#     print(child_conn.recv())#接收管道发送方的信息
#     child_conn.close()
#8.使用共享内存实现进程间数据的交换
# from multiprocessing import Process,Value,Array
# def f(n,a):
#     n.value = 3.1415927
#     for i in range(len(a)):
#         a[i] = a[i] * a[i]
# if __name__ == "__main__":
#     num = Value('d',0.0)        #实型
#     arr = Array('i',range(10))  #整型
#     p = Process(target=f,args=(num,arr))    #创建进程对象
#     p.start()
#     p.join()
#     print(num.value)
#     print(arr[:])
#9.使用Manager对象实现进程间数据交互,Manager控制拥有list,dict,Lock,RLock,Semaphore,Condition,Event,Queue,Value等对象的服务端进程
# from multiprocessing import Manager,Process
# def f(d,l,t):
#     d['name'] = 'Yaos'
#     d['age'] = 34
#     l.reverse()
#     t.value=23
# if __name__ == "__main__":
#     with Manager() as manager:
#         d = manager.dict()
#         l = manager.list(range(10))
#         t = manager.Value('i',0)
#         p = Process(target=f,args=(d,l,t))
#         p.start()
#         p.join()
#         for item in d.items():
#             print(item)
#         print(l)
#         print(t.value)
#10.进程同步技术与现场同步技术类似，可以使用Lock,Event对象
# from multiprocessing import Process,Event
# def f(e,i):
#     if e.is_set():
#         e.wait()
#         print('hello world',i)
#         e.clear()
#     else:
#         e.set()
# if __name__ == "__main__":
#     e = Event()
#     for num in range(6):
#         Process(target=f,args=(e,num)).start()
#11.MapReduce框架的使用---大数据处理
#一种编程模型，用于大规模数据集（大于1TB）的并行计算
# import os,os.path,time
# '''大文件分割'''
# def FileSplit(sourceFile,targetFile):
#     if not os.path.isfile(sourceFile):
#         print(sourceFile,' does not File!')
#         return
#     if not os.path.isdir(targetFile):
#         os.mkdir(targetFile)
#     tempData = []
#     number = 1000#切分后的每一个小文件包含number行数据
#     fileNum = 1
#     with open(sourceFile,'r',encoding='UTF-8') as srcFile:
#         dataLine = srcFile.readline().strip()
#         while dataLine:
#             for i in range(number):
#                 tempData.append(dataLine)
#                 dataLine = srcFile.readline()
#                 if not dataLine:
#                     break
#             desFile = os.path.join(targetFile,sourceFile[0:-4] + str(fileNum) + ".txt")
#             with open(desFile,'a+',encoding='UTF-8') as f:
#                 f.writelines(tempData)
#             tempData = []
#             fileNum = fileNum + 1
#
# if __name__ == "__main__":
#     FileSplit(sourceFile="test.txt",targetFile="test/SourceFileSplit")

'''12.使用Map处理数据'''
# import os,re,threading,time
# def Map(sourceFile):
#     if not os.path.exists(sourceFile):
#         print(sourceFile,'does not exist')
#         return
#     pattern = re.compile(r'[0-9]{4}/[0-9]{1,2}/[0-9]{1,2}')
#     result = {}
#     with open(sourceFile,'r',encoding='UTF-8') as srcFile:
#         for dataLine in srcFile:
#             r = pattern.findall(dataLine)#查找符合日期格式的字符串
#             if r:
#                 # result.get(r[0],0)：get()方法用于返回指定键的对应值，当键不存在时，返回指定特定的值；与setdefault()一样，当键不存在时，新增指定的值
#                 result[r[0]] = result.get(r[0],0) + 1
#     desFile = sourceFile.replace('SourceFileSplit','MapFile')[0:-4] + '_map.txt'
#     with open(desFile,'a+',encoding='UTF-8') as fp:
#         for k,v in result.items():
#             fp.write(k+':'+str(v)+'\n')
# if __name__ == "__main__":
#     desFolder = 'test/SourceFileSplit'
#     files = os.listdir(desFolder)
#     def Main(i):
#         Map(desFolder+'\\'+files[i])
#     fileNumber = len(files)
#     for i in range(fileNumber):#多线程处理
#         t = threading.Thread(target=Main,args=(i,))
#         t.start()
'''13.使用Reducer获取最终数据'''
# from os.path import isdir
# from os import listdir
#
# def Reduce(sourceFolder,targetFile):
#     if not isdir(sourceFolder):
#         print(sourceFolder,'does not exist.')
#         return
#     result = {}
#     #仅处理匹配的文件
#     allFiles = [sourceFolder + '\\' + f for f in listdir(sourceFolder) if f.endswith('_map.txt')]
#     for f in allFiles:
#         with open(f,'r',encoding='UTF-8') as fp:
#             for line in fp:
#                 line = line.strip()
#                 if not line:
#                     continue
#                 key,value = line.split(':')
#                 result[key] = result.get(key,0) + int(value)
#     with open(targetFile,'w',encoding='UTF-8') as fp:
#         for k,v in result.items():
#             fp.write(k+':'+str(v)+'\n\n')
# if __name__ == "__main__":
#     Reduce('test\\MapFile','test\\result.txt')

#14.优化上面MapRedurce处理，需要进行分割文件，直接使用Map,Reduce
# import os,re,time
# def Map(sourceFile):
#     if not os.path.exists(sourceFile):
#         print(sourceFile,' does not exist.')
#         return
#     pattern = re.compile(r'[0-9]{4}/[0-9]{1,2}/[0-9]{1,2}')
#     result = {}
#     with open(sourceFile,'r',encoding='UTF-8') as srcFile:
#         for dataLine in srcFile:
#             r = pattern.findall(dataLine)
#             if r:
#                 print(r[0],',',1)
# Map('test.txt')
#15.Redurce文件
# import os,sys
# def Reduce(targetFile):
#     result = {}
#     for line in sys.stdin:
#         riqi,shuliang = line.strip().split(',')
#         result[riqi] = result.get(riqi,0)+1
#     with open(targetFile,'w',encoding='UTF-8') as fp:
#         for k,v in result.items():
#             fp.write(k+':'+str(v)+'\n')
# Reduce('result.txt')

本文旨在学习python中有关线程的基础知识，上述代码都是一个个相关的实例，仅供参考。