Python If-Condition 与 While-True 无限循环冲突

Question

我想问一下，我现在在做python3 http web server。然而，当它停留在“while-true”时，它在“if-condition”上有问题。当我想使用其他“if条件”时，程序卡在“while-true”，无法继续其他程序。

from http.server import BaseHTTPRequestHandler, HTTPServer
import subprocess


Request = None

class RequestHandler_httpd(BaseHTTPRequestHandler):
  def do_GET(self):
    global Request
    messagetosend = bytes('Hello Worldddd!',"utf")
    self.send_response(200)
    self.send_header('Content-Type', 'text/plain')
    self.send_header('Content-Length', len(messagetosend))
    self.end_headers()
    self.wfile.write(messagetosend)
    Request = self.requestline
    Request = Request[5 : int(len(Request)-9)]
    print(Request)
    if Request == 'onAuto':
        
        def always_run():
            subprocess.run("python3 satu.py ;", shell=True)
            subprocess.run("python3 dua.py ;", shell=True)
            
        while True:
            always_run() #the program stuck here and other if cannot be used
        
    
    if Request == 'onFM':
        subprocess.run("python3 satu.py ;", shell=True)
      
    if Request == 'onQR':
        subprocess.run("python3 dua.py ;", shell=True)
      
    if Request == 'offSYS':
        subprocess.run("python3 OFF_SYSTEM.py ;", shell=True)
      
    return


server_address_httpd = ('X.X.X.X',8080) #my private address
httpd = HTTPServer(server_address_httpd, RequestHandler_httpd)
print('Starting Server')
httpd.serve_forever()

Answer 1

正如 JonSG 评论的那样。你的

while True:
   always_run()

正在阻止您的代码的进一步执行。所以你必须在一个单独的线程中运行它：

import threading

class AlwaysThread(threading.Thread):
   def __init__(self):
      super(AlwaysThread, self).__init__()
      self.stopThread = False

   def run(self):
      self.stopThread = False
      while not self.stopThread:
         always_run()

# where you previously have done the endless loop
t = AlwaysThread()
t.start()

# stop it with t.stopThread = True

我也会使用 switch 语句而不是 if cascade。