python - Pip 升级失败，错误为 : Invalid requirement: '\xe2\x80\x93upgrade'

Question

我尝试使用以下方式升级 pip:

pip install –upgrade setuptools pip wheel

并出现以下错误:

DEPRECATION: Python 2.7 will reach the end of its life on January 1st, 2020. Please upgrade your Python as Python 2.7 won't be maintained after that date. A future version of pip will drop support for Python 2.7. More details about Python 2 support in pip, can be found at https://pip.pypa.io/en/latest/development/release-process/#python-2-support

ERROR: Invalid requirement: '\xe2\x80\x93upgrade'

完成后:

sudo pip install --upgrade setuptools pip wheel

我收到以下错误:

ERROR: Could not install packages due to an EnvironmentError: [('/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/_markerlib/markers.pyc', '/private/tmp/pip-uninstall-MzJySA/markers.pyc', "[Errno 1] Operation not permitted: '/private/tmp/pip-uninstall-MzJySA/markers.pyc'"), ('/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/_markerlib/init.py', '/private/tmp/pip-uninstall-MzJySA/init.py', "[Errno 1] Operation not permitted: '/private/tmp/pip-uninstall-MzJySA/init.py'"), ('/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/_markerlib/markers.py', '/private/tmp/pip-uninstall-MzJySA/markers.py', "[Errno 1] Operation not permitted: '/private/tmp/pip-uninstall-MzJySA/markers.py'"), ('/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/_markerlib/init.pyc', '/private/tmp/pip-uninstall-MzJySA/init.pyc', "[Errno 1] Operation not permitted: '/private/tmp/pip-uninstall-MzJySA/init.pyc'"), ('/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/_markerlib', '/private/tmp/pip-uninstall-MzJySA', "[Errno 1] Operation not permitted: '/private/tmp/pip-uninstall-MzJySA'")]

如何在 OSX 上修复该问题？

Answer 1

\xe2\x80\x93 是 Unicode 字符 EN DASH U+2013 的 UTF-8 编码它与通常表示选项名称的双 ASCII 减号字符完全不同(尽管在视觉上隐约相似)。

您需要--upgrade，而不是--upgrade。

有时，例如博客平台“有帮助地”用“排版”HTML 等价物替换 ASCII 序列，例如破折号、引号等，这样更赏心悦目，但此类替换永远不应该在 code 跨度中执行。

在 MacOS 上，我强烈警告不要尝试升级系统提供的文件；有时，出于很好的原因，它们会被固定到旧版本，无论如何，如果你弄乱系统文件，你将危及你正确安装 future 操作系统升级的能力。相反，尝试使用一个隔离的环境，您可以在其中升级各个库，而无需触及系统提供的库 - 随 Python 3 安装的 venv 包是基准解决方案，但还有其他替代方案，例如第三种 - party virtualenv 包(如果你真的还停留在 Python 2 上!表示哀悼)、pyenv、miniconda 等