Python 多线程超详细到位总结

import threading
# 从数据库提取数据的类
class Scheduler():
    def __init__(self):
        self._lock = threading.RLock()
        self.start = 0
        # 每次取10000条数据
        self.step = 10000

    def getdata(self):
        # 上锁，以免多线程同时对数据库进行访问，取出重复数据
        self._lock.acquire()
        # 进行取数据操作
        data = 'select * from table' \
               'where id between self.start and self.start + self.step'
        # 取完数据后，指针后移
        self.start += self.step
        self._lock.release()
        return data

# 处理数据的过程写在这里
def processdata():
    # 从该实例中提取数据
    data = scheduler.getdata()
    while data:
        # 进行处理数据的具体操作:
        # 去重、补缺、运算...只要还有数据，本线程就继续取新数据
        # 然后再获取数据，进行循环
        data = scheduler.getdata()

# 创建多线程，threads_num为创建的线程数
def threads_scheduler(threads_num):
    threads = []
    for i in range(threads_num):
        # 创建线程
        td = threading.Thread(target=processdata, name='th'+str(i+1))
        threads.append(td)
    for t in threads:
        # 启动线程
        t.start()
        for t in threads:
            # 子线程守护
            t.join()
            print('数据已全部处理成功')

if __name__=='__main__':
    # 实例化一个调度器，初始化参数
    scheduler = Scheduler()
    # 创建线程，开始处理数据
    threads_scheduler(4)

from time import sleep
import threading

def music(music_name):
    for i in range(2):
        print('正在听{}'.fORMat(music_name))
        sleep(1)
        print('music over')

def game(game_name):
    for i in range(2):
        print('正在玩{}'.format(game_name))
        sleep(3)
        print('game over')

threads = []
t1 = threading.Thread(target=music,args=('稻香',))
threads.append(t1)
t2 = threading.Thread(target=game,args=('飞车',))
threads.append(t2)

if __name__ == '__main__':
    for t in threads:
        # t.setDaemon(True)
        t.start()
        
    for t in threads:
        t.join()
    print('主线程运行结束')

from time import sleep
# fun为定义的待运行函数
with ThreadPoolExecutor(max_workers=5) as executor:
    ans = executor.map(fun, [遍历值])
    for res in ans:
        print(res)

with ThreadPoolExecutor(max_workers=5) as executor:
    list = [遍历值]
    ans = [executor.submit(fun, i) for i in list]
    for res in as_completed(ans):
        print(res.result())

class Account:
    def __init__(self, card_id, balance):
        # 封装账户ID、账户余额的两个变量
        self.card_id= card_id
        self.balance = balance
        
def withdraw(account, money):
    # 进行加锁
    lock.acquire()
    # 账户余额大于取钱数目
    if account.balance >= money:
        # 吐出钞票
        print(threading.current_thread().name + "取钱成功！吐出钞票:" + str(money),end=' ')
        # 修改余额
        account.balance -= money
        print("\t余额为: " + str(account.balance))
    else:
        print(threading.current_thread().name + "取钱失败！余额不足")
    # 进行解锁
    lock.release()
# 创建一个账户，银行卡id为8888，存款1000元
acct = Account("8888" , 1000)

# 模拟两个对同一个账户取钱
# 在主线程中创建一把锁
lock = threading.Lock()
threading.Thread(name='窗口A', target=withdraw , args=(acct , 800)).start()
threading.Thread(name='窗口B', target=withdraw , args=(acct , 800)).start()

import threading

def main():
    lock.acquire()
    print('第一道锁')
    lock.acquire()
    print('第二道锁')
    lock.release()
    lock.release()
    
if __name__ == '__main__':
    lock = threading.Lock()
    main()

import threading

def main():
    lock.release()
    print("在子线程解锁后打印")
if __name__ == '__main__':
    lock = threading.Lock()
    lock.acquire()
    t = threading.Thread(target=main)
    t.start()

import threading
import time

def fun_1():
    print('开始')
    time.sleep(1)
    lock.acquire()
    print("第一道锁")
    fun_2()
    lock.release()
    
def fun_2():
    lock.acquire()
    print("第二道锁")
    lock.release()
    
if __name__ == '__main__':
    lock = threading.RLock()
    t1 = threading.Thread(target=fun_1)
    t2 = threading.Thread(target=fun_1)
    t1.start()
    t2.start()