Python多线程编程

thread模块

#!/usr/bin/python3

import _thread
import time

# Define a function for the thread
def print_time( threadName, delay):
   count = 0
   while count < 5:
      time.sleep(delay)
      count += 1
      print ("%s: %s" % ( threadName, time.ctime(time.time()) ))

# Create two threads as follows
try:
   _thread.start_new_thread( print_time, ("Thread-1", 2, ) )
   _thread.start_new_thread( print_time, ("Thread-2", 4, ) )
except:
   print ("Error: unable to start thread")

while 1:
   pass

输出

Thread-1: Wed Dec 26 14:43:54 2018
Thread-2: Wed Dec 26 14:43:56 2018
Thread-1: Wed Dec 26 14:43:56 2018
Thread-1: Wed Dec 26 14:43:58 2018
Thread-2: Wed Dec 26 14:44:00 2018
Thread-1: Wed Dec 26 14:44:00 2018
Thread-1: Wed Dec 26 14:44:02 2018
Thread-2: Wed Dec 26 14:44:04 2018
Thread-2: Wed Dec 26 14:44:08 2018
Thread-2: Wed Dec 26 14:44:12 2018

threading模块

#!/usr/bin/python3

import threading
import time

exitFlag = 0

class MyThread (threading.Thread):
   def __init__(self, threadID, name, counter):
      threading.Thread.__init__(self)
      self.threadID = threadID
      self.name = name
      self.counter = counter
   def run(self):
      print ("Starting " + self.name)
      print_time(self.name, self.counter, 5)
      print ("Exiting " + self.name)

def print_time(threadName, delay, counter):
   while counter:
      if exitFlag:
         threadName.exit()
      time.sleep(delay)
      print ("%s: %s" % (threadName, time.ctime(time.time())))
      counter -= 1

# Create new threads
thread1 = MyThread(1, "Thread-1", 1)
thread2 = MyThread(2, "Thread-2", 2)

# Start new Threads
thread1.start()
thread2.start()
thread1.join()
thread2.join()
print ("Exiting Main Thread")

输出

Starting Thread-2Starting Thread-1

Thread-1: Wed Dec 26 14:52:50 2018
Thread-2: Wed Dec 26 14:52:51 2018Thread-1: Wed Dec 26 14:52:51 2018

Thread-1: Wed Dec 26 14:52:52 2018
Thread-2: Wed Dec 26 14:52:53 2018
Thread-1: Wed Dec 26 14:52:54 2018
Thread-1: Wed Dec 26 14:52:55 2018
Exiting Thread-1
Thread-2: Wed Dec 26 14:52:56 2018
Thread-2: Wed Dec 26 14:52:58 2018
Thread-2: Wed Dec 26 14:53:00 2018
Exiting Thread-2
Exiting Main Thread

同步线程

#!/usr/bin/python3
# save file : MyThread2.py
import threading
import time

class MyThread2 (threading.Thread):
   def __init__(self, threadID, name, counter):
      threading.Thread.__init__(self)
      self.threadID = threadID
      self.name = name
      self.counter = counter
   def run(self):
      print ("Starting " + self.name)
      # Get lock to synchronize threads
      threadLock.acquire()
      print_time(self.name, self.counter, 3)
      # Free lock to release next thread
      threadLock.release()

def print_time(threadName, delay, counter):
   while counter:
      time.sleep(delay)
      print ("%s: %s" % (threadName, time.ctime(time.time())))
      counter -= 1

threadLock = threading.Lock()
threads = []

# Create new threads
thread1 = MyThread2(1, "Thread-1", 1)
thread2 = MyThread2(2, "Thread-2", 2)

# Start new Threads
thread1.start()
thread2.start()

# Add threads to thread list
threads.append(thread1)
threads.append(thread2)

# Wait for all threads to complete
for t in threads:
   t.join()
print ("Exiting Main Thread")

输出

Starting Thread-1Starting Thread-2

Thread-1: Wed Dec 26 14:54:58 2018
Thread-1: Wed Dec 26 14:55:00 2018
Thread-1: Wed Dec 26 14:55:01 2018
Thread-2: Wed Dec 26 14:55:03 2018
Thread-2: Wed Dec 26 14:55:05 2018
Thread-2: Wed Dec 26 14:55:07 2018
Exiting Main Thread

多线程优先级队列

#!/usr/bin/python3
#coding=utf-8

import queue
import threading
import time

exitFlag = 0

class MyQueue (threading.Thread):
   def __init__(self, threadID, name, q):
      threading.Thread.__init__(self)
      self.threadID = threadID
      self.name = name
      self.q = q
   def run(self):
      print ("Starting " + self.name)
      process_data(self.name, self.q)
      print ("Exiting " + self.name)

def process_data(threadName, q):
   while not exitFlag:
      queueLock.acquire()
      if not workQueue.empty():
         data = q.get()
         queueLock.release()
         print ("%s processing %s" % (threadName, data))
      else:
         queueLock.release()
         time.sleep(1)

threadList = ["Thread-1", "Thread-2", "Thread-3"]
nameList = ["One", "Two", "Three", "Four", "Five"]
queueLock = threading.Lock()
workQueue = queue.Queue(10)
threads = []
threadID = 1

# Create new threads
for tName in threadList:
   thread = MyQueue(threadID, tName, workQueue)
   thread.start()
   threads.append(thread)
   threadID += 1

# Fill the queue
queueLock.acquire()
for word in nameList:
   workQueue.put(word)
queueLock.release()

# Wait for queue to empty
while not workQueue.empty():
   pass

# Notify threads it's time to exit
exitFlag = 1

# Wait for all threads to complete
for t in threads:
   t.join()
print ("Exiting Main Thread")

输出

Starting Thread-1Starting Thread-3Starting Thread-2


Thread-3 processing One
Thread-1 processing TwoThread-2 processing Three

Thread-1 processing FourThread-3 processing FiveExiting Thread-2


Exiting Thread-1Exiting Thread-3

Exiting Main Thread