时间戳

首页 > 解决方案 > Python 无法访问我的 USB 设备 - 权限不足

python-3.x - Python 无法访问我的 USB 设备 - 权限不足

问题描述

Python 脚本无法将打印发送到我的 USB 爱普生收据打印机

我是 Ubuntu 的新手。我正在尝试将一些文本发送到通过 USB 连接到我的计算机的热敏标签打印机。按 F5 键在 Visual Studio Code 中执行代码后，出现以下错误

File "/home/hdadmin/Documents/Python/POS/env/lib/python3.6/site-packages/usb/backend/libusb1.py", line 595, in _check
raise USBError(_strerror(ret), ret, _libusb_errno[ret])
usb.core.USBError: [Errno 13] Access denied (insufficient permissions)

但是，如果我执行相同的代码：

sudo python3 -m test5.py

然后，它打印出来了。google了很多搜索，看来是和我的规则设置有关的问题，所以在/etc/udev/rules.d/printerRule.rules中做了如下规则

SUBSYSTEM=="usb", ATTRS{idVendor}=="1208", ATTRS{idProduct}=="3605",  MODE="0666", OWNER="hdadmin"

问题仍然存在。

我需要解决这个问题的原因是，我以后需要使用 pyinstaller 编译 Python 脚本。如果我现在编译

pyinstaller --onefile test5.py

编译过程会很好，但是运行编译文件时仍然不允许我使用usb设备。以下是完整的错误报告

(env) (base) hdadmin@HiddenDimsum:~/Documents/Python/POS$ cd /home/hdadmin/Documents/Python/POS ; env PYTHONIOENCODING=UTF-8 PYTHONUNBUFFERED=1 /home/hdadmin/Documents/Python/POS/env/bin/python3.6 /home/hdadmin/.vscode/extensions/ms-python.python-2019.9.34911/pythonFiles/ptvsd_launcher.py --default --client --host localhost --port 42379 /home/hdadmin/Documents/Python/POS/test4.py 
Traceback (most recent call last):
  File "/home/hdadmin/.vscode/extensions/ms-python.python-2019.9.34911/pythonFiles/ptvsd_launcher.py", line 43, in <module>
    main(ptvsdArgs)
  File "/home/hdadmin/.vscode/extensions/ms-python.python-2019.9.34911/pythonFiles/lib/python/ptvsd/__main__.py", line 432, in main
    run()
  File "/home/hdadmin/.vscode/extensions/ms-python.python-2019.9.34911/pythonFiles/lib/python/ptvsd/__main__.py", line 316, in run_file
    runpy.run_path(target, run_name='__main__')
  File "/usr/lib/python3.6/runpy.py", line 263, in run_path
    pkg_name=pkg_name, script_name=fname)
  File "/usr/lib/python3.6/runpy.py", line 96, in _run_module_code
    mod_name, mod_spec, pkg_name, script_name)
  File "/usr/lib/python3.6/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "/home/hdadmin/Documents/Python/POS/test4.py", line 2, in <module>
    printer = Usb(1208, 3605)
  File "/home/hdadmin/Documents/Python/POS/env/lib/python3.6/site-packages/escpos/printer.py", line 51, in __init__
    self.open()
  File "/home/hdadmin/Documents/Python/POS/env/lib/python3.6/site-packages/escpos/printer.py", line 62, in open
    check_driver = self.device.is_kernel_driver_active(0)
  File "/home/hdadmin/Documents/Python/POS/env/lib/python3.6/site-packages/usb/core.py", line 1061, in is_kernel_driver_active
    self._ctx.managed_open()
  File "/home/hdadmin/Documents/Python/POS/env/lib/python3.6/site-packages/usb/core.py", line 102, in wrapper
    return f(self, *args, **kwargs)
  File "/home/hdadmin/Documents/Python/POS/env/lib/python3.6/site-packages/usb/core.py", line 120, in managed_open
    self.handle = self.backend.open_device(self.dev)
  File "/home/hdadmin/Documents/Python/POS/env/lib/python3.6/site-packages/usb/backend/libusb1.py", line 786, in open_device
    return _DeviceHandle(dev)
  File "/home/hdadmin/Documents/Python/POS/env/lib/python3.6/site-packages/usb/backend/libusb1.py", line 643, in __init__
    _check(_lib.libusb_open(self.devid, byref(self.handle)))
  File "/home/hdadmin/Documents/Python/POS/env/lib/python3.6/site-packages/usb/backend/libusb1.py", line 595, in _check
    raise USBError(_strerror(ret), ret, _libusb_errno[ret])
usb.core.USBError: [Errno 13] Access denied (insufficient permissions)

由于我是 Linux 和 Ubuntu 的新手，因此我需要帮助和建议，以便获得连接到我计算机的 USB 设备的许可。预期的结果是，我应该能够运行 test5.py 而无需

须藤python3 -m test5.py

标签： python-3.xlinuxvisual-studio-codeubuntu-18.04

解决方案

感谢消费税。你完全正确。我的错误是在创建 .rule 期间

SUBSYSTEM=="usb", ATTRS{idVendor}=="1208", ATTRS{idProduct}=="3605",  MODE="0666",   OWNER="hdadmin"

相反，它应该如下所示，其中 GROUP="users"。我误读了“用户”并将其替换为用户名。我将规则更改为如下：

SUBSYSTEMS=="usb", ATTRS{idVendor}=="1fc9", ATTRS{idProduct}=="2016", GROUP="users", MODE="0666"

然后在终端写

 $ sudo udevadm control --reload

并重新启动计算机。

推荐阅读