如何从 Homebrew 重新安装 python@2？

Question

我在使用 brew 时遇到了 openssl 和 python@2 问题，这里已经解释了（未解决）。重新安装 Python 和 openssl 的文档化解决方法不起作用，所以我决定卸载并重新安装 Python。

问题是，当您尝试使用 brew 安装 Python 2 时，您会收到以下消息：

brew install python@2
Error: No available formula with the name "python@2"
==> Searching for a previously deleted formula (in the last month)...
Warning: homebrew/core is shallow clone. To get complete history run:
  git -C "$(brew --repo homebrew/core)" fetch --unshallow

python@2 was deleted from homebrew/core in commit 028f11f9e:
  python@2: delete (https://github.com/Homebrew/homebrew-core/issues/49796)
  EOL 1 January 2020.
  We gave it 1 month more to live so that people had time to migrate.
  All in all, developers had 11 years to do their migration.
  You can use the `brew extract` command and maintain python@2 in your own
  tap if necessary:
  https://docs.brew.sh/How-to-Create-and-Maintain-a-Tap

To show the formula before removal run:
  git -C "$(brew --repo homebrew/core)" show 028f11f9e^:Formula/python@2.rb

If you still use this formula consider creating your own tap:
  https://docs.brew.sh/How-to-Create-and-Maintain-a-Tap

不幸的是，我仍然有许多依赖于 Brew 的 python@2 的 brew 公式。那些包括awscli, letsencrypt, prsshuttle例如

aws
zsh: /usr/local/bin/aws: bad interpreter: /usr/local/opt/python@2/bin/python2.7: no such file or directory

我不知道如何使用brew extract他们记录的这个命令来重新安装 Python@2。它需要一个公式和一个水龙头。我想公式是python@2. 我不确定水龙头需要什么。

此外，重新安装水龙头，例如aws或letsencrypt也不能很好地工作。

重新安装awscli( brew reinstall awscli) 后，运行 aws 命令仍然会出错。

aws
/usr/local/Cellar/awscli/2.0.0/libexec/lib/python3.8/site-packages/jmespath/visitor.py:32: SyntaxWarning: "is" with a literal. Did you mean "=="?
  if x is 0 or x is 1:
/usr/local/Cellar/awscli/2.0.0/libexec/lib/python3.8/site-packages/jmespath/visitor.py:32: SyntaxWarning: "is" with a literal. Did you mean "=="?
  if x is 0 or x is 1:
/usr/local/Cellar/awscli/2.0.0/libexec/lib/python3.8/site-packages/jmespath/visitor.py:34: SyntaxWarning: "is" with a literal. Did you mean "=="?
  elif y is 0 or y is 1:
/usr/local/Cellar/awscli/2.0.0/libexec/lib/python3.8/site-packages/jmespath/visitor.py:34: SyntaxWarning: "is" with a literal. Did you mean "=="?
  elif y is 0 or y is 1:
/usr/local/Cellar/awscli/2.0.0/libexec/lib/python3.8/site-packages/jmespath/visitor.py:260: SyntaxWarning: "is" with a literal. Did you mean "=="?
  if original_result is 0:
usage: aws [options] <command> <subcommand> [<subcommand> ...] [parameters]
To see help text, you can run:

  aws help
  aws <command> help
  aws <command> <subcommand> help
aws: error: the following arguments are required: command

Answer 1

似乎自制软件的工作人员真的尽可能地在 macOS 上使用 Python 2.7 变得尽可能困难。

1. 链接的brew extract链接真的没有帮助，您需要在此处寻找有关如何从提取的源中制作自己的水龙头的答案。
2. 链接提交：028f11f9e 是错误的，因为它包含已删除的文件。
3. 由于包名称中的@，该brew extract命令甚至无法正常工作。

解决方案非常简单，您只需要下载最新的已知提交并从该文件安装：

cd ~
wget https://raw.githubusercontent.com/Homebrew/homebrew-core/86a44a0a552c673a05f11018459c9f5faae3becc/Formula/python@2.rb
brew install python@2.rb
rm python@2.rb

可能会有关于“不稳定”的警告，我不明白这是因为 Git 历史记录中的提交尽可能稳定。

Answer 2

对于Apple 在 macOS 12.3 中删除系统 python 后出现在这里的用户，以下是如何安装和运行 python2 和 python3。

蟒蛇2

python, python2-> 蟒蛇 2.7

# Download/run the legacy macOS installer (pick which one for your sys)
https://www.python.org/downloads/release/python-2718/

# Add pip for python2.7
curl https://bootstrap.pypa.io/pip/2.7/get-pip.py -o get-pip2.py
python2 get-pip2.py

# Optionally check for pip updates (in case of post-eol patches)
python2 -m pip install --upgrade pip

# Optionally add the helpers like easy_install back onto your path
# In your ~/.zprofile or whatever bash/shell profile equivalent
PATH="/Library/Frameworks/Python.framework/Versions/2.7/bin:${PATH}"
export PATH

# Optionally add some helpers while editing shell profile
alias pip2="python2 -m pip"
alias venv2="virtualenv -p python2"
alias venv3="virtualenv -p python3"

# Optionally some apple-specific std libraries are missing, search
# and download them. Example: plistlib.py
curl https://raw.githubusercontent.com/python/cpython/2.7/Lib/plistlib.py -o /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plistlib.py

# Lastly, there is no symlink /usr/bin/python anymore
# /usr/bin is system protected so you can't add one either
# 
# Change your programs to use /usr/local/bin/python
# or google how to disable macOS SIP to make a symlink in /usr/bin

蟒蛇3

python3-> 蟒蛇3

brew update
brew install python3

# Add pip for python 3 in case it is missing
curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py
python3 get-pip.py

# Check for pip updates
python3 -m pip install --upgrade pip

# Optionally add a helper in ~/.zprofile
alias venv3="virtualenv -p python3"

测试一下

~ % python --version
Python 2.7.18

~ % python2 --version
Python 2.7.18

~ % python3 --version
Python 3.9.10

# Running older python2
python2 -m pip install...
python2 ...

# Testing the venv2 alias from above
venv2 foo
source foo/bin/activate
pip -V # pip 20... from... python2.7
pip install -y -r req.txt
pip uninstall -y -r req.txt
pip freeze
deactivate

# Testing the venv3 alias from above
venv3 foo3
source foo3/bin/activate
pip -V # pip22... from ...python3.9
pip install -y -r req.txt
pip uninstall -y -r req.txt
pip freeze
deactivate

通过卸载/重新安装进行故障排除

# Credit to https://www.macupdate.com/app/mac/5880/python/uninstall  
# for many of the tips in this section.

# Sometimes there are problems related to accepting xcode 
# tool agreement. Open XCode to make sure it finished 
# installing its tool updates.

# Remove old python Application installs
# open the apps dir and delete Python 2, 3 via Finder
open /Applications

# Remove old brew installs 
brew list | grep python
brew uninstall python
brew uninstall python3

# find/remove lingering unlinked kegs
ls /usr/local/Cellar/ | grep python 

# Cleanup binaries
sudo rm -rf /Library/Frameworks/Pyth*
rm /usr/local/bin/pip*

# Cleanup symlinks
which -a python # check results, and rm each one
which -a python2 # check results, and rm each one
which -a python3 # check results, and rm each one

brew cleanup # prunes symlinks

Answer 3

如何python@2从本地水龙头安装

以下方法适用于 的当前版本 ( c9b8a3ef6) brew：

$ brew tap-new <user>/homebrew-python2
$ brew extract python@2 <user>/homebrew-python2
$ brew install /usr/local/Homebrew/Library/Taps/<user>/homebrew-python2/Formula/python@2.7.17.rb

该brew tap-new命令在/usr/local/Homebrew/Library/Taps/<user>/homebrew-python2. 水龙头名称需要一个<user>和一个<repo>由 分隔的组件/。实际值是任意的。上面的命名遵循如何创建和维护 Tap 中的约定。如果您想将点击推送到 GitHub，您可以使用您的 GitHub 用户名作为用户。没有必要推送到 GitHub（并且没有在上面的说明中执行）。

这些brew extract命令从 repos 历史中提取最新版本的公式到给定的（本地）tap 中。在我们的情况下python@2.7.17.rb被提取。

该brew install命令最终会安装公式。

为什么这是必要的？

上面讨论的方法（从 GitHub 提交 URL 安装旧版本的公式）不再适用python@2于brew( c9b8a3ef6)的当前版本，它会产生以下错误：

$ brew install https://raw.githubusercontent.com/Homebrew/homebrew-core/86a44a0a552c673a05f11018459c9f5faae3becc/Formula/python@2.rb
Updating Homebrew...
==> Auto-updated Homebrew!
Updated Homebrew from 88f17b8b6 to c9b8a3ef6.
...
Error: Calling Installation of python@2 from a GitHub commit URL is disabled! Use 'brew extract python@2' to stable tap on GitHub instead.

Answer 4

请检查以下命令（我在 macOS 10.13 上使用它，对于较新的 macOS，它可能无需源代码编译即可运行）：

brew install pr0d1r2/python2/python@2.7.17 --build-from-source

Answer 5

这对我在 m1(12.3.1) 上工作：
不要使用brew，直接从python官方网站下载。
这个问题折磨了我很久:(

Answer 6

您可以使用以下pyenv命令安装 python：

brew install pyenv
pyenv install 2.7.18

（可选）将其设置为您的全局默认值：

pyenv global 2.7.18

关于为什么使用pyenv比brew用于管理您的 python 安装更好的好文章。

Answer 7

对于后代，在 macOS 10.15（2021 年 5 月）上工作：

/usr/local/bin/brew tap-new ${USER}/homebrew-python2

/usr/local/bin/brew extract python@2 ${USER}/homebrew-python2

/usr/local/bin/brew install /usr/local/Homebrew/Library/Taps/${USER}/homebrew-python2/Formula/python@2.7.17.rb

# https://github.com/Homebrew/brew/issues/5734#issuecomment-464705002
/usr/local/bin/brew untap ${USER}/python2