Python TCP客户端-服务端通信：带参数斐波那契功能实现求助

Got it, let's break down how to add this parameterized Fibonacci feature to your TCP client-server setup. The core idea is defining a clear message protocol between client and server so they can understand both the function request and its arguments—something you didn't need for your earlier parameter-less functions.

1. Define a Simple Message Protocol #

Since we need to send both a command and its parameters, JSON is the easiest, most robust choice here. It lets us package structured data into a string that’s easy to serialize and parse. Our protocol will look like this:

• Client sends: {"command": "fibonacci", "params": {"n": 10}} (plus a newline to mark the end of the message, since TCP is a stream protocol)
• Server responds with either a success message: {"status": "success", "result": 55} or an error: {"status": "error", "message": "Invalid number"}

2. Server Implementation #

Here’s how to modify your server to handle the parameterized Fibonacci request:

import socket
import json

# Your existing Fibonacci function
def FIBONACCI(n):
    if n == 0:
        return 0
    elif n == 1:
        return 1
    else:
        return FIBONACCI(n-1) + FIBONACCI(n-2)

def handle_client_connection(conn):
    try:
        # Receive and decode the client's message
        raw_data = conn.recv(1024).decode('utf-8').strip()
        if not raw_data:
            return
        
        # Parse the JSON request
        request = json.loads(raw_data)
        command = request.get('command')

        if command == 'fibonacci':
            # Extract and validate the parameter
            n = request.get('params', {}).get('n')
            if isinstance(n, int) and n >= 0:
                result = FIBONACCI(n)
                response = json.dumps({'status': 'success', 'result': result})
            else:
                response = json.dumps({'status': 'error', 'message': 'Please enter a non-negative integer'})
        else:
            response = json.dumps({'status': 'error', 'message': 'Unknown command'})
        
        # Send the response back to the client
        conn.sendall((response + '\n').encode('utf-8'))
    except Exception as e:
        print(f"Error processing request: {str(e)}")
    finally:
        conn.close()

def start_server():
    host = '127.0.0.1'
    port = 65432

    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as server_socket:
        server_socket.bind((host, port))
        server_socket.listen()
        print(f"Server running on {host}:{port}")
        
        while True:
            conn, addr = server_socket.accept()
            with conn:
                print(f"Connected to client at {addr}")
                handle_client_connection(conn)

if __name__ == "__main__":
    start_server()

3. Client Implementation #

Now update your client to prompt for the Fibonacci number and send the structured request:

import socket
import json

def start_client():
    host = '127.0.0.1'
    port = 65432

    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as client_socket:
        client_socket.connect((host, port))
        print("Connected to server!")

        # Show function menu
        print("\nAvailable Functions:")
        print("1. Calculate Fibonacci Number")
        choice = input("Enter your choice (1): ")

        if choice == '1':
            # Get valid input from user
            while True:
                try:
                    n = int(input("Enter a non-negative integer: "))
                    if n < 0:
                        print("Please enter a number greater than or equal to 0.")
                        continue
                    break
                except ValueError:
                    print("Invalid input—please enter an integer.")
            
            # Build and send the JSON request
            request = json.dumps({
                'command': 'fibonacci',
                'params': {'n': n}
            }) + '\n'  # Newline marks end of message
            client_socket.sendall(request.encode('utf-8'))

            # Receive and parse the server's response
            raw_response = client_socket.recv(1024).decode('utf-8').strip()
            response = json.loads(raw_response)

            if response['status'] == 'success':
                print(f"Fibonacci({n}) = {response['result']}")
            else:
                print(f"Server Error: {response['message']}")
        else:
            print("Invalid choice—exiting.")

if __name__ == "__main__":
    start_client()

Key Notes for Your Transition #

• Message Delimiting: We added a newline (\n) to each message because TCP sends data as a stream—this helps both sides know when a complete message ends.
• Input Validation: We added checks for non-integer or negative inputs on both client and server to avoid crashes.
• Scalability: This pattern works for other parameterized functions too—just add more command cases in the server and update the client menu.

内容的提问来源于stack exchange，提问作者nor