python多线程

python标准库中有多线程:threading包.本文分面向过程和面向对量两种方式记录一下多线程的写法:

1.面向过程:

 1 # A program to simulate selling tickets in multi-thread way
 2 # Written by Vamei
 3 
 4 import threading
 5 import time
 6 import os
 7 
 8 # This function could be any function to do other chores.
 9 def doChore():
10     time.sleep(0.5)
11 
12 # Function for each thread
13 def booth(tid):
14     global i
15     global lock
16     while True:
17         lock.acquire()                # Lock; or wait if other thread is holding the lock
18         if i != 0:
19             i = i - 1                 # Sell tickets
20             print(tid,':now left:',i) # Tickets left
21             doChore()                 # Other critical operations
22         else:
23             print("Thread_id",tid," No more tickets")
24             os._exit(0)              # Exit the whole process immediately
25         lock.release()               # Unblock
26         doChore()                    # Non-critical operations
27 
28 # Start of the main function
29 i    = 100                           # Available ticket number 
30 lock = threading.Lock()              # Lock (i.e., mutex)
31 
32 # Start 10 threads
33 threads = []
34 for k in range(10):
35     new_thread = threading.Thread(target=booth,args=(k,))   # Set up thread; target: the callable (function) to be run, args: the argument for the callable 
36     threads.append(new_thread)
37 for t in threads:                                            # run the thread
38     t.start()
39 for t in threads:                                            # wait all thread end
40     t.join()

2.面向对象:

# A program to simulate selling tickets in multi-thread way
# Written by Vamei

import threading
import time
import os

# This function could be any function to do other chores.
def doChore():
    time.sleep(0.5)

# Function for each thread
class BoothThread(threading.Thread):
    def __init__(self, tid, monitor):
        self.tid          = tid
        self.monitor = monitor
        threading.Thread.__init__(self)
    def run(self):
        while True:
            monitor['lock'].acquire()                          # Lock; or wait if other thread is holding the lock
            if monitor['tick'] != 0:
                monitor['tick'] = monitor['tick'] - 1          # Sell tickets
                print(self.tid,':now left:',monitor['tick'])   # Tickets left
                doChore()                                      # Other critical operations
            else:
                print("Thread_id",self.tid," No more tickets")
                os._exit(0)                                    # Exit the whole process immediately
            monitor['lock'].release()                          # Unblock
            doChore()                                          # Non-critical operations

# Start of the main function
monitor = {'tick':100, 'lock':threading.Lock()}

# Start 10 threads
threads = []
for k in range(10):
    new_thread = BoothThread(k, monitor)
    threads.append(new_thread)
for t in threads:                                            # run the thread
    t.start()
for t in threads:                                            # wait all thread end
    t.join()

Ps:

python中print不是线程保护的,多线程输出的时候会乱掉,可以用sys.stdout.write()函数替换