Python下载实战技巧的技术文章大纲

检查网络连接状态

使用Python的socket模块可以快速检查网络是否连通。以下代码尝试连接Google的DNS服务器（8.8.8.8）来判断网络状态：

python 复制代码

import socket

def check_internet(host="8.8.8.8", port=53, timeout=3):
    try:
        socket.setdefaulttimeout(timeout)
        socket.socket(socket.AF_INET, socket.SOCK_STREAM).connect((host, port))
        return True
    except Exception as ex:
        print(f"No internet connection: {ex}")
        return False

if check_internet():
    print("Network is active")
else:
    print("No network connection")

获取当前网络配置

在Windows系统上，可以通过ipconfig命令获取网络配置。使用Python的subprocess模块调用系统命令：

python 复制代码

import subprocess

def get_network_config():
    try:
        result = subprocess.run(["ipconfig", "/all"], 
                              capture_output=True, 
                              text=True,
                              check=True)
        print(result.stdout)
    except subprocess.CalledProcessError as e:
        print(f"Error getting network config: {e.stderr}")

get_network_config()

重置网络适配器

在Windows系统中重置网络适配器的完整方案：

python 复制代码

import os

def reset_network_adapters():
    commands = [
        "netsh winsock reset",
        "netsh int ip reset",
        "ipconfig /release",
        "ipconfig /renew",
        "ipconfig /flushdns"
    ]
    
    for cmd in commands:
        try:
            print(f"Executing: {cmd}")
            os.system(cmd)
        except Exception as e:
            print(f"Error executing {cmd}: {e}")

reset_network_adapters()

检查特定端口连通性

测试特定主机和端口的网络连通性：

python 复制代码

import socket
from concurrent.futures import ThreadPoolExecutor

def test_port(host, port):
    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
        s.settimeout(2)
        try:
            s.connect((host, port))
            return f"Port {port} is open"
        except:
            return f"Port {port} is closed"

def scan_ports(host, ports):
    with ThreadPoolExecutor(max_workers=10) as executor:
        results = executor.map(test_port, [host]*len(ports), ports)
        for result in results:
            print(result)

scan_ports("example.com", [80, 443, 22, 3389])

网络速度测试

使用speedtest-cli库进行网络速度测试：

python 复制代码

import speedtest

def run_speed_test():
    st = speedtest.Speedtest()
    st.get_best_server()
    
    download = st.download() / 1_000_000  # Convert to Mbps
    upload = st.upload() / 1_000_000      # Convert to Mbps
    
    print(f"Download Speed: {download:.2f} Mbps")
    print(f"Upload Speed: {upload:.2f} Mbps")
    print(f"Ping: {st.results.ping} ms")

run_speed_test()

网络流量监控

使用psutil库监控网络流量：

python 复制代码

import psutil
import time

def monitor_network(duration=60, interval=1):
    start = time.time()
    initial = psutil.net_io_counters()
    
    while time.time() - start < duration:
        time.sleep(interval)
        current = psutil.net_io_counters()
        
        sent = (current.bytes_sent - initial.bytes_sent) / 1_000_000  # MB
        recv = (current.bytes_recv - initial.bytes_recv) / 1_000_000  # MB
        
        print(f"Upload: {sent:.2f} MB | Download: {recv:.2f} MB")
        initial = current

monitor_network(duration=10)

网络故障排除日志

创建完整的网络诊断日志：

python 复制代码

import datetime
import platform
import subprocess

def create_network_log():
    timestamp = datetime.datetime.now().strftime("%Y%m%d_%H%M%S")
    filename = f"network_diagnostic_{timestamp}.log"
    
    with open(filename, "w") as f:
        f.write(f"=== System Information ===\n")
        f.write(f"OS: {platform.system()} {platform.release()}\n")
        f.write(f"Python: {platform.python_version()}\n\n")
        
        f.write("=== Network Configuration ===\n")
        try:
            ipconfig = subprocess.run(["ipconfig", "/all"], 
                                    capture_output=True, 
                                    text=True)
            f.write(ipconfig.stdout + "\n")
        except Exception as e:
            f.write(f"Error getting ipconfig: {str(e)}\n")
            
        f.write("\n=== Connection Tests ===\n")
        test_commands = [
            ("Ping Google", "ping 8.8.8.8 -n 4"),
            ("Traceroute Google", "tracert 8.8.8.8"),
            ("NSLookup Google", "nslookup google.com")
        ]
        
        for name, cmd in test_commands:
            f.write(f"\n{name}:\n")
            try:
                result = subprocess.run(cmd.split(), 
                                      capture_output=True, 
                                      text=True)
                f.write(result.stdout)
                if result.stderr:
                    f.write(f"Error: {result.stderr}\n")
            except Exception as e:
                f.write(f"Error executing {cmd}: {str(e)}\n")
    
    print(f"Diagnostic log created: {filename}")

create_network_log()