为什么 httpserver 不会与 tkinter 在单独的线程上

Question

首先，我是 python 的新手，所以如果我做了一些非常愚蠢的事情，请告诉我。

我有这个桌面应用程序运行在 raspberyy pi 上使用 python 和 tkinter 开发用于 GUI 并且由于项目中的新要求，它需要能够接收远程执行某些操作的命令。

为此，我想向项目添加一个 http 服务器

在我的主脚本中我有这个：

from tkinter import *  
from http.server import BaseHTTPRequestHandler, HTTPServer
import threading

# Create GUI app and define general properties
window = Tk()
window.attributes("-fullscreen", True)
window.config(cursor="none")

winWidth = int(window.winfo_screenwidth() * 1)
winHeight = int(window.winfo_screenheight() * 1)

window.geometry(f"{winWidth}x{winHeight}")

class HttpHandler(BaseHTTPRequestHandler):
    def do_GET(self):
        self.send_response(200)
        self.send_header("Content-type", "text/html")
        self.end_headers()
        self.wfile.write(bytes("<html><head><title>https://pythonbasics.org</title></head>", "utf-8"))
        self.wfile.write(bytes("<p>Request: %s</p>" % self.path, "utf-8"))
        self.wfile.write(bytes("<body>", "utf-8"))
        self.wfile.write(bytes("<p>This is an example web server.</p>", "utf-8"))
        self.wfile.write(bytes("</body></html>", "utf-8"))

 
#Start HTTP Server
webServer = HTTPServer(('localhost', 9080), HttpHandler)
print('running http server on port: ', 9080)
threading.Thread(target=webServer.serve_forever, daemon=True) 
    
window.mainloop()

现在代码非常基础，只是为了得到它运行ning 但我的想法是稍后对 http 请求执行 IO 操作。例如 /api/lights/on 会触发 GPIO。

我不得不使用 threading.Thread 因为否则脚本会阻塞 webServer.serve_forever()

通过使用线程，它不再阻塞并正确显示 GUI。还有 'netstat -lnt' 我可以看出 http 服务器正在监听指定的端口。

当我在 http://127.0.0.1:9080/ 打开浏览器时，浏览器从未得到响应。

我是不是做错了什么？

Answer 1

我发现了两个错误

你忘记导入 threading 所以它给出了错误信息
```
import threading
```

您创建了线程但忘记启动它

t = threading.Thread(target=webServer.serve_forever, daemon=True)
t.start()

顺便说一句：

你可以更好地组织代码。
参见：PEP 8 --Style Guide for Python Code

import threading
import tkinter as tk  # PEP8: `import *` is not preferred
from http.server import BaseHTTPRequestHandler, HTTPServer

# --- classes ---

class HttpHandler(BaseHTTPRequestHandler):
    def do_GET(self):
        self.send_response(200)
        self.send_header("Content-type", "text/html")
        self.end_headers()
        self.wfile.write(bytes("<html><head><title>https://pythonbasics.org</title></head>", "utf-8"))
        self.wfile.write(bytes("<p>Request: %s</p>" % self.path, "utf-8"))
        self.wfile.write(bytes("<body>", "utf-8"))
        self.wfile.write(bytes("<p>This is an example web server.</p>", "utf-8"))
        self.wfile.write(bytes("</body></html>", "utf-8"))

# --- functions ---

# empty

# --- main ---

webServer = HTTPServer(('localhost', 9080), HttpHandler)
print('running http server: http://localhost:9080')  # some consoles will display URL as clickable so it is easier to run browser
t = threading.Thread(target=webServer.serve_forever, daemon=True)
t.start()

window = tk.Tk()

#window.attributes("-fullscreen", True)
window.config(cursor="none")

#winWidth = int(window.winfo_screenwidth() * 1)
#winHeight = int(window.winfo_screenheight() * 1)
#window.geometry(f"{winWidth}x{winHeight}")
    
window.mainloop()

我只是想知道使用 http.server 是否是个好主意。如果你想通过网页访问，那么用 Flask 创建页面会更简单。如果您想发送小命令，那么使用服务器 MQTT 可能会更简单而不是 HTTP。我已经使用了一些 IoT 台设备 MQTT

其他问题可能导致线程之间的通信。 Tkinter 不喜欢在子线程中运行所以你不能直接在服务器线程中访问小部件，它需要队列将值发送到主线程并且 tkinter 需要 after(millisecond, function) 定期检查队列以获取命令。

编辑：

使用 queue 将信息从 http server 发送到 tkinter 并将其显示在小部件 Text

中的版本

import threading
import tkinter as tk  # PEP8: `import *` is not preferred
from http.server import BaseHTTPRequestHandler, HTTPServer
import queue

# --- classes ---

class HttpHandler(BaseHTTPRequestHandler):
    def do_GET(self):
        self.send_response(200)
        self.send_header("Content-type", "text/html")
        self.end_headers()
        self.wfile.write(bytes("<html><head><title>https://pythonbasics.org</title></head>", "utf-8"))
        self.wfile.write(bytes("<p>Request: %s</p>" % self.path, "utf-8"))
        self.wfile.write(bytes("<body>", "utf-8"))
        self.wfile.write(bytes("<p>This is an example web server.</p>", "utf-8"))
        self.wfile.write(bytes("</body></html>", "utf-8"))

        q.put("Request: %s" % self.path)  # put in `queue`
        
# --- functions ---

def check_queue():
    if not q.empty():
        text.insert('end', q.get()+'\n') # get from `queue` and put in `Text`
    window.after(100, check_queue)  # check again after 100ms
    
# --- main ---

q = queue.Queue()

webServer = HTTPServer(('localhost', 9080), HttpHandler)
print('running http server: http://localhost:9080')  # some consoles will display URL as clickable so it is easier to run browser
t = threading.Thread(target=webServer.serve_forever, daemon=True)
t.start()

window = tk.Tk()

text = tk.Text(window)
text.pack()

check_queue()

window.mainloop()

编辑：

同Flask。它可以获取数据：args、json、表单、文件等

import queue
import threading
import tkinter as tk  # PEP8: `import *` is not preferred
from flask import Flask, request, render_template_string

# --- classes ---

    
# --- functions ---

app = Flask(__name__)

#@app.route('/')
@app.route('/', defaults={'path': ''})
@app.route('/<path:path>')
def index(path):

    print('path:', path)
    print(f'Request: {request.method} {request.url}')
    print('args:', request.args)
    print('form:', request.form)
    print('data:', request.data)
    print('json:', request.json)
    print('files:', request.files)
    
    q.put(f'Request: {request.method} {request.url}')  # put in `queue`

    return render_template_string('''<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>https://pythonbasics.org</title>
</head>
<body>
<p>Request: {{ request.method }} {{ request.url }}</p>
<p>This is an example web server.</p>
</body>
</html>''', request=request)

def check_queue():
    if not q.empty():
        text.insert('end', q.get()+'\n') # get from `queue` and put in `Text`
    window.after(100, check_queue)  # check again after 100ms
    
# --- main ---

q = queue.Queue()

print('running http server: http://localhost:9080')  # some consoles will display URL as clickable so it is easier to run browser
t = threading.Thread(target=app.run, args=('localhost', 9080), daemon=True)
t.start()

window = tk.Tk()

text = tk.Text(window)
text.pack()

check_queue()

window.mainloop()

但现在的问题是：如果可以在 flask

中完成，为什么要使用 tkinter

为什么 httpserver 不会与 tkinter 在单独的线程上

Why httpserver won't on separate thread with tkinter

python

tkinter

httpserver