# Information Technology
# 摩尔定律 -- 任何买不起的电子产品,在18月后价格会降低一半,甚至更多。
# 原因:电子产品每隔18个月,性能会翻翻。
# 安迪比尔定律:安迪给你的东西,比尔都会给你拿走。硬件性能起来了,但是软件跟不上。
# 所以:当软件更新时,硬件的性能需求将会提升。
# 反摩尔定律:一个IT公司如果今天和18个月前卖掉同样多的、同样的产品,它的营业额就要降一半。IT界把它称为反摩尔定律。
# 线程加锁
import time from threading import Thread, Lock class Account(object): def __init__(self): self._balance = 0 self._lock = Lock() @property def balance(self): return self._balance def deposit(self, money): """当多个线程同时访问一个资源的时候,就有可能因为竞争资源导致状态崩溃 被多个线程访问的资源,称为临界资源,对临界资源的访问需要加上保护。 """ if money: self._lock.acquire() # 加锁,开始是并行,加锁后变成串行,解锁后变成并行。 try: new_balance = self._balance + money time.sleep(0.01) self._balance = new_balance finally: self._lock.release() class AddMoneyThread(Thread): def __init__(self, account): super(AddMoneyThread, self).__init__() self._account = account def run(self): self._account.deposit(1) def main(): account = Account() tlist = [] for _ in range(100): t = AddMoneyThread(account) tlist.append(t) t.start() for t in tlist: t.join() print(‘%d元‘ % account.balance) if __name__ == ‘__main__‘: main()
五车争霸赛
from random import randint from threading import Thread import pygame import time class Color(object): BLACK = (0, 0, 0) WHITE = (255, 255, 255) GRAY = (242, 242, 242) @staticmethod def random_color(): r = randint(0, 255) g = randint(0, 255) b = randint(0, 255) return r, g, b class Car(object): def __init__(self, x, y, color): self._x = x self._y = y self._color = color def move(self): if self._x <= 870: self._x += randint(1, 10) return True return False def draw(self, screen): pygame.draw.rect(screen, self._color, [self._x, self._y, 80, 40], 0) def main(): class BackgroundThread(Thread): def run(self): nonlocal screen is_go_on = True while is_go_on: screen.fill(Color.GRAY) pygame.draw.line(screen, Color.BLACK, (130, 0), (130, 600), 4) pygame.draw.line(screen, Color.BLACK, (950, 0), (950, 600), 4) for car in cars: car.draw(screen) pygame.display.flip() time.sleep(0.05) for car in cars: if not car.move(): is_go_on = False cars = [] for i in range(5): temp = Car(50, i * 120 + 50, Color.random_color()) cars.append(temp) pygame.init() screen = pygame.display.set_mode((1000, 600)) pygame.display.set_caption(‘五车争霸赛‘) BackgroundThread(daemon=True).start() running = True while running: for event in pygame.event.get(): if event.type == pygame.QUIT: running = False pygame.quit() if __name__ == ‘__main__‘: main()