Python 3.x 如何在程序端关闭python进程

我无法在程序结束时关闭在进程中正常运行的串行连接。（在windows/VSCode和Ctrl-C上）

我收到一条错误消息，大多数情况下，端口在程序的下一次启动时已经打开

我必须先完成运行过程吗

class serialOne(Process):
    def __init__(self, serial_port, debug, baudrate=57600, timeout=1):
    ...

    def terminate(self):
        print("close ports")
        self.active = False
        self.ser.close()

    def run(self):
        while self.active:
            self.initCom()
            self.readCom()
            time.sleep(0.005)

    def main():
        global processList
        global debug

        while True:
            if debug == True:
                print("main")
            time.sleep(1.0)

        for process in processList:
            process.terminate()

我的主要观点是：

def main():
    global processList
    global debug

    while True:
        if debug == True:
            print("main") # actually doing nothing
        time.sleep(1.0)

    for process in processList:
        process.terminate()

这是错误消息：

Process serialOne-1:
Traceback (most recent call last):
  File "C:\Users\dgapp\AppData\Local\Programs\Python\Python37-32\lib\multiprocessing\process.py", line 297, in _bootstrap
    self.run()
Traceback (most recent call last):
  File "e:\_python\rfid_jacky\simple_multiprocess_rfid_02.py", line 129, in run
    time.sleep(0.005)
  File "c:\Users\dgapp\.vscode\extensions\ms-python.python-2018.12.1\pythonFiles\ptvsd_launcher.py", line 45, in <module>
KeyboardInterrupt
    main(ptvsdArgs)
  File "c:\Users\dgapp\.vscode\extensions\ms-python.python-2018.12.1\pythonFiles\lib\python\ptvsd\__main__.py", line 265, in main
    wait=args.wait)
  File "c:\Users\dgapp\.vscode\extensions\ms-python.python-2018.12.1\pythonFiles\lib\python\ptvsd\__main__.py", line 258, in handle_args
    debug_main(addr, name, kind, *extra, **kwargs)
  File "c:\Users\dgapp\.vscode\extensions\ms-python.python-2018.12.1\pythonFiles\lib\python\ptvsd\_local.py", line 45, in debug_main
    run_file(address, name, *extra, **kwargs)
  File "c:\Users\dgapp\.vscode\extensions\ms-python.python-2018.12.1\pythonFiles\lib\python\ptvsd\_local.py", line 79, in run_file
    run(argv, addr, **kwargs)
  File "c:\Users\dgapp\.vscode\extensions\ms-python.python-2018.12.1\pythonFiles\lib\python\ptvsd\_local.py", line 140, in _run
    _pydevd.main()
  File "c:\Users\dgapp\.vscode\extensions\ms-python.python-2018.12.1\pythonFiles\lib\python\ptvsd\_vendored\pydevd\pydevd.py", line 1925, in main
    debugger.connect(host, port)
  File "c:\Users\dgapp\.vscode\extensions\ms-python.python-2018.12.1\pythonFiles\lib\python\ptvsd\_vendored\pydevd\pydevd.py", line 1283, in run
    return self._exec(is_module, entry_point_fn, module_name, file, globals, locals)
  File "c:\Users\dgapp\.vscode\extensions\ms-python.python-2018.12.1\pythonFiles\lib\python\ptvsd\_vendored\pydevd\pydevd.py", line 1290, in _exec
    pydev_imports.execfile(file, globals, locals)  # execute the script
  File "c:\Users\dgapp\.vscode\extensions\ms-python.python-2018.12.1\pythonFiles\lib\python\ptvsd\_vendored\pydevd\_pydev_imps\_pydev_execfile.py", line 25, in execfile
    exec(compile(contents+"\n", file, 'exec'), glob, loc)
  File "e:\_python\rfid_jacky\simple_multiprocess_rfid_02.py", line 161, in <module>
    main()
  File "e:\_python\rfid_jacky\simple_multiprocess_rfid_02.py", line 140, in main
    time.sleep(1.0)
KeyboardInterrupt

Process serialOne-1：
回溯（最近一次呼叫最后一次）：
文件“C:\Users\dgapp\AppData\Local\Programs\Python\Python37-32\lib\multiprocessing\process.py”，第297行，在_bootstrap中
self.run（）
回溯（最近一次呼叫最后一次）：
文件“e:\\u python\rfid\u jacky\simple\u multiprocess\u rfid\u 02.py”，第129行，正在运行
睡眠时间（0.005）
文件“c:\Users\dgapp\.vscode\extensions\ms python.python-2018.12.1\pythonFiles\ptvsd_launcher.py”，第45行，在
键盘中断
干管（ptvsdArgs）
文件“c:\Users\dgapp\.vscode\extensions\ms python.python-2018.12.1\pythonFiles\lib\python\ptvsd\\ uuuuuu main_uuuu.py”，第265行，在main中
wait=args.wait）
文件“c:\Users\dgapp\.vscode\extensions\ms python.python-2018.12.1\pythonFiles\lib\python\ptvsd\\ uuuuu main\uuuuuu.py”，第258行，在句柄参数中
debug_main（地址、名称、种类、*extra、**kwargs）
文件“c:\Users\dgapp\.vscode\extensions\ms python.python-2018.12.1\pythonFiles\lib\python\ptvsd\\ u local.py”，第45行，在debug\ u main中
运行文件（地址、名称、*extra、**kwargs）
文件“c:\Users\dgapp\.vscode\extensions\ms python.python-2018.12.1\pythonFiles\lib\python\ptvsd\\ u local.py”，第79行，在运行文件中
运行（argv，addr，**kwargs）
文件“c:\Users\dgapp\.vscode\extensions\ms python.python-2018.12.1\pythonFiles\lib\python\ptvsd\\ u local.py”，第140行，正在运行
_pydevd.main（）
文件“c:\Users\dgapp\.vscode\extensions\ms python.python-2018.12.1\pythonFiles\lib\python\ptvsd\\u vendored\pydevd\pydevd.py”，主文件第1925行
调试器.connect（主机、端口）
运行文件“c:\Users\dgapp\.vscode\extensions\ms python.python-2018.12.1\pythonFiles\lib\python\ptvsd\\u vendored\pydevd\pydevd.py”，第1283行
返回self.\u exec（是模块、入口点、模块名称、文件、全局、局部）
文件“c:\Users\dgapp\.vscode\extensions\ms python.python-2018.12.1\pythonFiles\lib\python\ptvsd\\u vendored\pydevd\pydevd.py”，第1290行，在_exec中
pydev_imports.execfile（文件、全局、局部）#执行脚本
文件“c:\Users\dgapp\.vscode\extensions\ms python.python-2018.12.1\pythonFiles\lib\python\ptvsd\\u vendored\pydevd\\u pydev\u imps\\u pydev\u execfile.py”，execfile中第25行
exec（编译（内容+“\n”，文件，'exec'），全局，loc）
文件“e:\\u python\rfid\u jacky\simple\u multiprocess\u rfid\u 02.py”，第161行，在
main（）
文件“e:\\u python\rfid\u jacky\simple\u multiprocess\u rfid\u 02.py”，第140行，在main中
时间。睡眠（1.0）
键盘中断

当您按下

Ctrl+C

时，将引发

键盘中断

异常，并中断无限睡眠循环。但是，由于您没有捕获此异常，因此此循环之后的代码（使用

process.terminate（）

）永远不会被调用，这可能会导致您的问题

所以你有几个选择：

• 捕捉

  键盘中断

  ，并使用该中断退出inifite循环：

  def main():
      global processList
      global debug
  
      try:
          while True:
              if debug == True:
                  print("main") # actually doing nothing
              time.sleep(1.0)
      except KeyboardInterrupt:
          pass
  
      for process in processList:
          process.terminate()
  

  这很简单，可读性也很强

• 注册将在程序退出时运行的退出处理程序：

  import atexit
  
  @atexit.register
  def shutdown():
      global processList
  
      for process in processList:
          process.terminate()
  
  def main():
      global debug
  
      while True:
          if debug == True:
              print("main") # actually doing nothing
          time.sleep(1.0)
  

  哪一个更可靠，因为即使进程被另一个信号终止，它也能工作

当用户点击中断键时，会发生此错误

一个简单的解决方案是捕获异常：

while True:
    if debug == True:
        print("main") # actually doing nothing

    try:
        # do your things
    except KeyboardInterrupt:
        print("program was interrupted by user")
        break

您还可以使用

finally

关键字正确结束您的程序：

try:
    while True:
        # do your things    
except KeyboardInterrupt:
    print("program was interrupted by user")
    break
finally:
    close()  # this will always happen, even if an exception was raised