Python多线程

1. 

import time, threading

def loop():
    print("thread %s is running..." % threading.current_thread().name)
    n = 0
    while n < 5:
        n = n+1
        print("thread %s >>> %s"%(threading.current_thread().name, n))
        time.sleep(1)
    print("thread %s ended." % threading.current_thread().name)

print("thread %s running." % threading.current_thread().name)
t = threading.Thread(target=loop, name='LoopThread')
t.start()
t.join()
print("thread %s ended." % threading.current_thread().name)

2.

import time, threading
balance = 0


def change_it(n):
    global balance
    balance = balance + n
    balance = balance - n


def run_thread(n):
    for i in range(100000):
        # change_it(n)
        lock.acquire()
        try:
            change_it(n)
        finally:
            lock.release()


lock = threading.Lock()
t1 = threading.Thread(target=run_thread, args=(5,))
t2 = threading.Thread(target=run_thread, args=(8,))
t1.start()
t2.start()
t1.join()
t2.join()
print(balance)

3.

import threading

local_school = threading.local()


def process_student():
    std = local_school.student
    print("Hello, %s (in %s)" % (std, threading.current_thread().name))


def process_thread(name):
    local_school.student = name
    process_student()


t1 = threading.Thread(target=process_thread, args=('Alice',), name="Thread-A")
t2 = threading.Thread(target=process_thread, args=('Bob',), name="Thread-B")
t1.start()
t2.start()
t1.join()
t2.join()