defask_for_number():user_input=input("请输入一个整数(输入'quit'退出):")ifuser_input.lower()=='quit':print("程序结束。")returntry:number=int(user_input)print(f"你输入的数字是:{number}")ask_for_number()# 递归调用exceptValueError:print("无效输入,请输入一个整数或'quit'。")ask_for_num...
number=input('please enter a number: ') number=int(number) if number % 10==0: print("This number is an integer multiple of 10") else: print("This number isn't an integer multiple of 10") 1. 2. 3. 4. 5. 6. 7. 4.编写一个循环,提示用户输入一系列的比萨配料,并在用户输入'quit...
>>>greetings=['hello','hello','mello','yello','hello']>>>newGreetings=[]>>>forwordingreetings:...ifword=='hello':# Copy everything that is'hello'...newGreetings.append(word)...>>>greetings=newGreetings # Replace the original list.>>>print(greetings)['hello','hello','hello'] 这...
事实上,你几乎从来不希望你的程序从第一行代码开始,简单地执行每一行,一直到最后。流程控制语句可以决定在什么条件下执行哪些Python指令。 这些流程控制语句直接对应于流程图中的符号,所以我将提供本章中讨论的代码的流程图版本。图 2-1 显示了下雨时该做什么的流程图。沿着箭头所指的路线从头到尾走。 图2-1:告诉...
for i in range(10_000_000): num -= 1 # 自动解锁if __name__ == "__main__": lock = threading.Lock() subThread01 = threading.Thread(target=add) subThread02 = threading.Thread(target=sub) subThread01.start() subThread02.start() subThread01.join() subThread02.join() print("num...
3. 与Python关键字重名的标识符:Python有一些关键字(例如if、for、while等),这些关键字具有特殊的含义,不能用作标识符。例如,if是不合法的标识符。 4. 与内置函数或模块重名的标识符:Python有一些内置函数和模块(例如print、input、math等),这些内置函数和模块具有特殊的功能,不能用作标识符。例如,print是不合法...
for i in range(maxSubThreadNumber): subThreadIns = threading.Thread(target=task) subThreadIns.start() while currentRunThreadNumber < maxSubThreadNumber: notifyNumber = int( input("Please enter the number of threads that need to be notified to run:")) ...
lock.acquire()# 上锁lock.acquire()# 死锁# 不执行globalnumforiinrange(10_000_000): num +=1lock.release() lock.release()defsub(): lock.acquire()# 上锁lock.acquire()# 死锁# 不执行globalnumforiinrange(10_000_000): num -=1lock.release() ...
Condition() for i in range(maxSubThreadNumber): subThreadIns = threading.Thread(target=task) subThreadIns.start() while currentRunThreadNumber < maxSubThreadNumber: notifyNumber = int( input("Please enter the number of threads that need to be notified to run:")) with condLock: condLock....
positive integer (whose representation should not start with 0) that can be converted to a Roman number (hence be at most equal to 3999), or a valid Roman number; otherwise, the program should print out Hey, ask me something that's not impossible to do! and stop. If the input is as...