如何链接home brew python版本并将其设置为默认值

Question

我刚刚从MacPorts切换到HomeBrew.在安装了所有必需的XCode版本和其他软件后,我尝试使用自制软件安装python:我认为它已成功安装,但是当我这样做which python时仍然向我显示2.7.3我认为是Mountain Lion附带的版本.

which python
/usr/local/bin/python

python --version
Python 2.7.3

所以我试着再次安装

brew install python --framework --universal
Warning: python-2.7.5 already installed, it's just not linked

但是它说python 2.7.5已经安装而没有链接,我试着这样做 brew link python

这导致我遵循这样的信息,我不知道我应该做什么:

链接/usr/local/Cellar/python/2.7.5 ...警告:无法链接python.取消链接...

Error: Could not symlink file: /usr/local/Cellar/python/2.7.5/bin/smtpd2.py
Target /usr/local/bin/smtpd2.py already exists. You may need to delete it.
To force the link and overwrite all other conflicting files, do:
  brew link --overwrite formula_name

To list all files that would be deleted:
  brew link --overwrite --dry-run formula_name

Answer 1

安装python3后,brew install python3 我得到错误:

Error: An unexpected error occurred during the `brew link` step
The formula built, but is not symlinked into /usr/local
Permission denied @ dir_s_mkdir - /usr/local/Frameworks
Error: Permission denied @ dir_s_mkdir - /usr/local/Frameworks

输入brew link python3错误后:

Linking /usr/local/Cellar/python/3.6.4_3... Error: Permission denied @ dir_s_mkdir - /usr/local/Frameworks

解决问题:

sudo mkdir -p /usr/local/Frameworks
sudo chown -R $(whoami) /usr/local/*
brew link python3

在此之后,我可以通过输入打开python3 python3

(来自https://github.com/Homebrew/homebrew-core/issues/20985)

Answer 2

对于那些寻找使用brew重新链接版本的人，我发现这个命令很有用：

brew unlink python@3.9 && brew link python@3.10

可能会出现一些错误，例如：

Error: Could not symlink bin/pip3
Target /usr/local/bin/pip3
already exists. You may want to remove it:
  rm '/usr/local/bin/pip3'

To force the link and overwrite all conflicting files:
  brew link --overwrite python@3.10

To list all files that would be deleted:
  brew link --overwrite --dry-run python@3.10

因此，遵循brew建议并运行：

rm '/usr/local/bin/pip3'
brew link --overwrite python@3.10

刚刚为我工作。要检查符号链接是否正常，请运行：ls -l /usr/local/bin/python*，您应该看到类似以下内容：

/usr/local/bin/python3 -> ../Cellar/python@3.10/3.10.2/bin/python3
/usr/local/bin/python3-config -> ../Cellar/python@3.10/3.10.2/bin/python3-config
/usr/local/bin/python3.10 -> ../Cellar/python@3.10/3.10.2/bin/python3.10
/usr/local/bin/python3.10-config -> ../Cellar/python@3.10/3.10.2/bin/python3.10-config

Answer 3

如果你用过

brew install python

在'取消联系'之前你得到了

brew info python
/usr/local/Cellar/python/2.7.11

python -V
Python 2.7.10

这样做

brew unlink python && brew link python

并打开一个新的终端shell

python -V
Python 2.7.11

Answer 4

在终端中,键入:

brew link python

Answer 5

我认为您必须精确确定要与以下命令链接的版本brew link python：

brew link python 3

它会给你这样的错误：

Linking /usr/local/Cellar/python3/3.5.2... 
Error: Could not symlink bin/2to3-3.5
Target /usr/local/bin/2to3-3.5
already exists. 

您可能要删除它：

rm '/usr/local/bin/2to3-3.5'

要强制链接并覆盖所有冲突文件：

brew link --overwrite python3

列出所有将被删除的文件：

brew link --overwrite --dry-run python3

但是您必须复制/粘贴命令以强制链接，即：

brew link --overwrite python3

我认为您必须安装了版本（较新）。

Answer 6

在OS X High Sierra上，我必须这样做：

sudo install -d -o $(whoami) -g admin /usr/local/Frameworks
brew uninstall --ignore-dependencies python
brew install python
python --version # should work, returns 2.7, which is a Python thing (it's weird, but ok)

归功于https://gist.github.com/irazasyed/7732946#gistcomment-2235469

我认为这比递归锁定/ usr / local目录要好，但这可能会解决其他问题;）

Answer 7

此答案适用于在 Mac OS X El Capitan 上将 Python 2.7.10 升级到 Python 2.7.11。在终端类型上：

brew unlink python

在终端上输入后

brew install python