如何在Raspberry Pi 4上检测U盘插入、获取路径并通过pyusb列出文件

一、检测U盘插入并获取挂载路径 #

静态检测（一次性扫描） #

通过读取系统挂载信息文件/proc/mounts，过滤出U盘对应的挂载路径，适合无需实时监听的场景：

import os

def detect_usb_drives():
    usb_drives = []
    with open('/proc/mounts', 'r') as f:
        for line in f.readlines():
            parts = line.strip().split()
            # 匹配常见U盘文件系统及树莓派默认挂载目录
            if parts[2] in ('vfat', 'ext4', 'ntfs') and '/media/pi/' in parts[1]:
                usb_drives.append({
                    'device': parts[0],
                    'mount_path': parts[1]
                })
    return usb_drives

# 调用示例
usb_devices = detect_usb_drives()
if usb_devices:
    for dev in usb_devices:
        print(f"设备: {dev['device']}, 挂载路径: {dev['mount_path']}")
else:
    print("未检测到U盘")

实时监听插入/拔出事件 #

如果需要实时感知U盘的插拔动作，可以使用pyudev库（需先安装：pip install pyudev），注意此方法需要root权限运行：

import pyudev
from time import sleep

def monitor_usb_events():
    context = pyudev.Context()
    monitor = pyudev.Monitor.from_netlink(context)
    monitor.filter_by(subsystem='block', device_type='disk')

    for device in iter(monitor.poll, None):
        if device.action == 'add' and device.attributes.get('removable') == b'1':
            # 等待系统完成挂载
            sleep(2)
            usb_devices = detect_usb_drives()
            if usb_devices:
                print(f"U盘插入，挂载路径: {usb_devices[-1]['mount_path']}")
        elif device.action == 'remove':
            print("U盘已拔出")

if __name__ == '__main__':
    monitor_usb_events()

二、列出U盘内的所有文件 #

注意：pyusb是底层USB设备通信库，不负责文件系统操作，读取U盘文件需通过挂载路径使用标准文件系统库实现：

使用os.walk遍历 #

import os

def list_usb_files(mount_path):
    file_info_list = []
    for root, _, files in os.walk(mount_path):
        for file in files:
            full_path = os.path.join(root, file)
            stat = os.stat(full_path)
            file_info_list.append({
                'name': file,
                'full_path': full_path,
                'size_bytes': stat.st_size,
                'modified_time': stat.st_mtime
            })
    return file_info_list

# 调用示例
usb_devices = detect_usb_drives()
if usb_devices:
    for dev in usb_devices:
        files = list_usb_files(dev['mount_path'])
        print(f"\n{dev['mount_path']} 内的文件:")
        for f in files:
            print(f"{f['name']} - {f['size_bytes']} bytes")

使用pathlib（更简洁的方式） #

from pathlib import Path

def list_usb_files_pathlib(mount_path):
    file_info_list = []
    for item in Path(mount_path).rglob('*'):
        if item.is_file():
            stat = item.stat()
            file_info_list.append({
                'name': item.name,
                'full_path': str(item),
                'size_bytes': stat.st_size,
                'modified_time': stat.st_mtime
            })
    return file_info_list

# 调用示例
usb_devices = detect_usb_drives()
if usb_devices:
    for dev in usb_devices:
        files = list_usb_files_pathlib(dev['mount_path'])
        print(f"\n{dev['mount_path']} 内的文件:")
        for f in files:
            print(f"{f['name']} - {f['size_bytes']} bytes")

注意事项 #

• 若U盘为NTFS格式，需先安装驱动：sudo apt install ntfs-3g
• 实时监听代码需以root权限运行（如sudo python3 your_script.py）
• 挂载路径可能因系统配置不同有所变化，若/media/pi/下未找到，可检查/mnt/目录或自定义挂载点

内容的提问来源于stack exchange，提问作者Ron