lock

from multiprocessing import Process, Lock
import json
import time


def search(i):
    with open('data', 'r', encoding='utf8') as f:
        dic = json.load(f)
        num = dic.get('ticket_num')
    print(f'{i},您好!当前票数为：{num}')
    # return dic


def buy(i):
    with open('data', 'r', encoding='utf8') as f:
        dic = json.load(f)
    # dic = search(i)
    time.sleep(1)
    if dic.get('ticket_num') > 0:
        dic['ticket_num'] -= 1
        with open('data', 'w', encoding='utf8') as f :
            json.dump(dic, f)
        print(f'{i},您已购票成功！')
    else:
        print(f'{i},不好意思，票已售完！')


def run(i, suo):
    search(i)
    suo.acquire()
    buy(i)
    suo.release()


if __name__ == '__main__':
    suo = Lock()
    for i in range(1, 4):
        p = Process(target=run, args=(i, suo))
        p.start()