PHP转Python开发者：无框架用Python开发Web应用可行吗？

Absolutely! You absolutely can build web applications using pure Python, no frameworks needed. This is actually a fantastic approach for learning, since it forces you to understand the core mechanics of HTTP requests, responses, and how web servers handle communication—stuff that frameworks abstract away.

Let’s walk through a few simple examples using Python’s built-in http.server module, which lets you create basic web servers right out of the box.

1. Hello World Web Page #

The simplest example is a server that returns a "Hello World" HTML page for every request:

from http.server import BaseHTTPRequestHandler, HTTPServer

class HelloHandler(BaseHTTPRequestHandler):
    def do_GET(self):
        # Send response status code
        self.send_response(200)
        # Send headers
        self.send_header('Content-type', 'text/html')
        self.end_headers()
        # Send the response body
        self.wfile.write(b"<html><body><h1>Hello, World!</h1></body></html>")

def run(server_class=HTTPServer, handler_class=HelloHandler, port=8000):
    server_address = ('', port)
    httpd = server_class(server_address, handler_class)
    print(f"Starting server on port {port}...")
    try:
        httpd.serve_forever()
    except KeyboardInterrupt:
        httpd.server_close()
        print("Server stopped.")

if __name__ == '__main__':
    run()

Save this as hello_server.py, run it with python hello_server.py, then visit http://localhost:8000 in your browser. You’ll see your Hello World page!

2. Simple Counter (with in-memory state) #

To build a counter that increments every time you visit the page, you’ll need to track state. Since we’re not using a database or framework, we can use a global variable (note: this will reset when you restart the server, which is fine for learning):

from http.server import BaseHTTPRequestHandler, HTTPServer

# Global variable to track the count
counter = 0

class CounterHandler(BaseHTTPRequestHandler):
    global counter
    
    def do_GET(self):
        global counter
        counter += 1
        
        self.send_response(200)
        self.send_header('Content-type', 'text/html')
        self.end_headers()
        
        response = f"<html><body><h1>Count: {counter}</h1></body></html>"
        self.wfile.write(response.encode('utf-8'))

def run(port=8000):
    server_address = ('', port)
    httpd = HTTPServer(server_address, CounterHandler)
    print(f"Starting counter server on port {port}...")
    try:
        httpd.serve_forever()
    except KeyboardInterrupt:
        httpd.server_close()
        print("Server stopped.")

if __name__ == '__main__':
    run()

Each time you refresh http://localhost:8000, the count will go up by 1.

3. Basic JSON API #

For a simple API that returns JSON data (e.g., a user object or status info), you can set the correct Content-type header and send JSON-encoded text:

from http.server import BaseHTTPRequestHandler, HTTPServer
import json

class APIHandler(BaseHTTPRequestHandler):
    def do_GET(self):
        # Check the path to serve different endpoints
        if self.path == '/api/user':
            user_data = {
                'id': 1,
                'name': 'Alice',
                'email': 'alice@example.com'
            }
            self.send_response(200)
            self.send_header('Content-type', 'application/json')
            self.end_headers()
            # Convert dict to JSON string and encode to bytes
            self.wfile.write(json.dumps(user_data).encode('utf-8'))
        else:
            # Handle 404 for unknown paths
            self.send_response(404)
            self.send_header('Content-type', 'text/html')
            self.end_headers()
            self.wfile.write(b"<html><body><h1>404 Not Found</h1></body></html>")

def run(port=8000):
    server_address = ('', port)
    httpd = HTTPServer(server_address, APIHandler)
    print(f"Starting API server on port {port}...")
    try:
        httpd.serve_forever()
    except KeyboardInterrupt:
        httpd.server_close()
        print("Server stopped.")

if __name__ == '__main__':
    run()

Visit http://localhost:8000/api/user and you’ll get a JSON response. Try any other path, and you’ll get a 404 error.

A few notes to keep in mind: #

• The http.server module is meant for development and learning only—it’s not secure or efficient enough for production use.
• As you scale beyond these simple examples, you’ll quickly realize why frameworks exist: handling routing, request parsing, sessions, databases, etc., manually gets tedious fast. But for learning the basics, this is perfect.
• You can also explore the cgi module if you want to handle form data, but that’s a bit more old-school.

So yes, pure Python is totally capable of building simple web pages and APIs—this is a great way to get a solid understanding of how web tech works before diving into frameworks.

内容的提问来源于stack exchange，提问作者Ali Marasizadeh