ifname=='Alice':print('Hi, Alice.')else:print('Hello, stranger.') 图2-3 显示了这段代码的流程图。 图2-3:一个else语句的流程图 elif语句 虽然只有if或else子句中的一个会执行,但您可能希望执行多个可能子句中的一个。elif语句是一个else if语句,总是跟在一个if或另一个elif语句之后。它提供了另...
As soon as user enter the or input the word ‘exit’, the if condition becomes true whichif user_input.lower() == ‘exit’:then the code of the if the condition is executed, the first line of code isprint(“Exiting the program.”)which prints a message on the terminal “Exiting the...
缩进必须一致(推荐 4 空格)。if是逻辑控制的核心,必须注意缩进和条件顺序。 elif和else是可选的,且else后面不能跟条件。 条件顺序:先判断范围小的条件,再判断大的范围(如先x > 20,再x > 10)。 避免冗余条件:例如if x > 0 and x > 5→ 直接写x > 5。 二、Python 注释 编写程序时经常有一些代码块...
Without daemon threads, you'd have to keep track of them, and tell them to exit, before your program can completely quit. By setting them as daemon threads, you can let them run and forget about them, and when your program quits, any daemon threads are killed automatically. 1#_*_coding...
ifname== "main": producer = producer() consumer = consumer() producer.start() consumer.start() producer.join() consumer.join() (译者在这里添加一段。乍一看这段代码好像会死锁,因为 condition.acquire() 之后就在 .wait() 了,好像会一直持有锁。其实 .wait() 会将锁释放,然后等待其他线程 .notify...
p.daemon:默认值为False,如果设为True,代表p为后台运行的守护进程,当p的父进程终止时,p也随之终止,并且设定为True后,p不能创建自己的新进程,必须在p.start()之前设置p.name:进程的名称p.pid:进程的pidp.exitcode:进程在运行时为None、如果为–N,表示被信号N结束(了解即可)p.authkey:进程的身份验证键,默认...
You can give an extra condition filter to do "conditional watchpoints". Pass a functionfunc(obj)which returnsTrueif you want to trigger the callback towhenofwatch a =0watch(a, when=lambdax: x >0) a =-1# Won't triggera =1# Trigger ...
...iflen(target)>1:sub=target[1]myclass="%sCLI"%sub.capitalize()eliftarget[0]=='ansible':sub='adhoc'myclass='AdHocCLI'else:raiseAnsibleError("Unknown Ansible alias: %s"%me)try:mycli=getattr(__import__("ansible.cli.%s"%sub,fromlist=[myclass]),myclass)...cli=mycli(args)exit_cod...
# Python program killing# thread using daemonimportthreadingimporttimeimportsysdeffunc():whileTrue:time.sleep(0.5)print('Thread alive, but it will die on program termination')t1=threading.Thread(target=func)t1.daemon=Truet1.start()time.sleep(2)sys.exit() ...
if name == 'Alice': print('Hi, Alice.') else: print('Hello, stranger.') 图2-3 显示了这段代码的流程图。 图2-3:一个else语句的流程图 elif语句 虽然只有if或else子句中的一个会执行,但您可能希望执行多个可能子句中的一个。elif语句是一个else if语句,总是跟在一个if或另一个elif语句之后。它...