使用PIP安装Bunch库失败，请求解决方法

看起来你在Python 3.12环境下安装bunch库时碰了壁，我来帮你拆解问题并给出可行的解决办法～

先抓准你遇到的核心错误：

ValueError: invalid mode: 'rU'

这个问题的根源很明确：Python 3.12已经彻底移除了'rU'这个过时的文件打开模式（它原本是用来启用通用换行符支持的，而Python 3.0+之后默认就已经支持通用换行符了），但PyPI上现有的bunch 1.0.1版本是2017年发布的老版本，代码里还在使用'rU'，所以在3.12环境下编译时直接报错。

接下来给你几个解决方向，按推荐程度排序：

方案1：使用兼容Python 3.12的替代库（最推荐） #

bunch库已经多年没有维护了，建议直接切换到功能类似且活跃维护的替代库munch，它完全兼容Python 3.12，用法和bunch几乎一致，安装命令：

pip install munch

举个简单的用法例子，和bunch的体验无缝衔接：

from munch import Munch
obj = Munch(name="test", value=123)
print(obj.name)  # 输出 test

方案2：修改bunch源码后本地安装 #

如果你一定要用原版bunch，可以手动修复源码里的兼容性问题后再安装：

1. 先下载bunch的源码包到本地：

   pip download bunch --no-deps
   

2. 解压下载好的bunch-1.0.1.zip压缩包
3. 打开解压目录里的setup.py文件，找到使用open(..., 'rU')的代码行（对应报错里的第11行），把模式'rU'改成'r'
4. 进入解压后的目录，执行本地安装命令：

   pip install .
   

方案3：降级Python版本到3.11或更低 #

如果你的项目对Python版本没有硬性要求，可以把Python降级到3.11或更早的版本，这些版本还保留了对'rU'模式的支持，之后再执行pip install bunch就能正常安装了。

最后附上你提供的完整错误日志供参考：

C:\Coding1\Coding>pip install --trusted-host pypi.python.org bunch
Defaulting to user installation because normal site-packages is not writeable
Collecting bunch
Using cached bunch-1.0.1.zip (11 kB)
Installing build dependencies ... done
Getting requirements to build wheel ... error
error: subprocess-exited-with-error

× Getting requirements to build wheel did not run successfully.
│ exit code: 1
╰─> [20 lines of output]
Traceback (most recent call last):
File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.12_3.12.2288.0_x64__qbz5n2kfra8p0\Lib\site-packages\pip_vendor\pyproject_hooks_in_process_in_process.py", line 353, in <module>
main()
File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.12_3.12.2288.0_x64__qbz5n2kfra8p0\Lib\site-packages\pip_vendor\pyproject_hooks_in_process_in_process.py", line 335, in main
json_out['return_val'] = hook(**hook_input['kwargs'])
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.12_3.12.2288.0_x64__qbz5n2kfra8p0\Lib\site-packages\pip_vendor\pyproject_hooks_in_process_in_process.py", line 118, in get_requires_for_build_wheel
return hook(config_settings)
^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\aayus\AppData\Local\Temp\pip-build-env-dd90kil7\overlay\Lib\site-packages\setuptools\build_meta.py", line 334, in get_requires_for_build_wheel
return self._get_build_requires(config_settings, requirements=[])
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Users\aayus\AppData\Local\Temp\pip-build-env-dd90kil7\overlay\Lib\site-packages\setuptools\build_meta.py", line 304, in _get_build_requires
self.run_setup()
File "C:\Users\aayus\AppData\Local\Temp\pip-build-env-dd90kil7\overlay\Lib\site-packages\setuptools\build_meta.py", line 522, in run_setup
super().run_setup(setup_script=setup_script)
File "C:\Users\aayus\AppData\Local\Temp\pip-build-env-dd90kil7\overlay\Lib\site-packages\setuptools\build_meta.py", line 320, in run_setup
exec(code, locals())
File "<string>", line 11, in <module>
ValueError: invalid mode: 'rU'
[end of output]

note: This error originates from a subprocess, and is likely not a problem with pip.
error: subprocess-exited-with-error

× Getting requirements to build wheel did not run successfully.
│ exit code: 1
╰─> See above for output.

note: This error originates from a subprocess, and is likely not a problem with pip.

备注：内容来源于stack exchange，提问作者Aayush Arora