如何修复安装 Python 时出现的错误消息“`brew link` 步骤未成功完成”？

Question

我用这个命令安装了 brew：

/bin/bash -c "$(curl -fsSL (here was rest of the link)

安装成功后，我开始安装python：

brew install python3

这是代码然后我得到了以下错误：

Error: The `brew link` step did not complete successfully
The formula built, but is not symlinked into /usr/local
Could not symlink bin/2to3
Target /usr/local/bin/2to3
already exists. You may want to remove it:
  rm '/usr/local/bin/2to3'

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

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

Possible conflicting files are:
/usr/local/bin/2to3 -> /Library/Frameworks/Python.framework/Versions/3.8/bin/2to3
/usr/local/bin/idle3 -> /Library/Frameworks/Python.framework/Versions/3.8/bin/idle3
/usr/local/bin/pydoc3 -> /Library/Frameworks/Python.framework/Versions/3.8/bin/pydoc3
/usr/local/bin/python3 -> /Library/Frameworks/Python.framework/Versions/3.8/bin/python3
/usr/local/bin/python3-config -> /Library/Frameworks/Python.framework/Versions/3.8/bin/python3-config
==> /usr/local/Cellar/python/3.7.7/bin/python3 -s setup.py --no-user-cfg install --force --verbose --install-scripts=/usr/local/Cellar/python/3.7.7/bin --install-lib=/usr/local/lib/python3.7/site-packages
==> /usr/local/Cellar/python/3.7.7/bin/python3 -s setup.py --no-user-cfg install --force --verbose --install-scripts=/usr/local/Cellar/python/3.7.7/bin --install-lib=/usr/local/lib/python3.7/site-packages
==> /usr/local/Cellar/python/3.7.7/bin/python3 -s setup.py --no-user-cfg install --force --verbose --install-scripts=/usr/local/Cellar/python/3.7.7/bin --install-lib=/usr/local/lib/python3.7/site-packages
==> Caveats
Python has been installed as
  /usr/local/bin/python3

Unversioned symlinks `python`, `python-config`, `pip` etc. pointing to
`python3`, `python3-config`, `pip3` etc., respectively, have been installed into
  /usr/local/opt/python/libexec/bin

You can install Python packages with
  pip3 install <package>
They will install into the site-package directory
  /usr/local/lib/python3.7/site-packages

See: https://docs.brew.sh/Homebrew-and-Python
==> Summary
????  /usr/local/Cellar/python/3.7.7: 4,006 files, 61.2MB
==> Caveats
==> openssl@1.1
A CA file has been bootstrapped using certificates from the system
keychain. To add additional certificates, place .pem files in
  /usr/local/etc/openssl@1.1/certs

and run
  /usr/local/opt/openssl@1.1/bin/c_rehash

openssl@1.1 is keg-only, which means it was not symlinked into /usr/local,
because macOS provides LibreSSL.

If you need to have openssl@1.1 first in your PATH run:
  echo 'export PATH="/usr/local/opt/openssl@1.1/bin:$PATH"' >> ~/.bash_profile

For compilers to find openssl@1.1 you may need to set:
  export LDFLAGS="-L/usr/local/opt/openssl@1.1/lib"
  export CPPFLAGS="-I/usr/local/opt/openssl@1.1/include"

==> readline
readline is keg-only, which means it was not symlinked into /usr/local,
because macOS provides BSD libedit.

For compilers to find readline you may need to set:
  export LDFLAGS="-L/usr/local/opt/readline/lib"
  export CPPFLAGS="-I/usr/local/opt/readline/include"

==> sqlite
sqlite is keg-only, which means it was not symlinked into /usr/local,
because macOS already provides this software and installing another version in
parallel can cause all kinds of trouble.

If you need to have sqlite first in your PATH run:
  echo 'export PATH="/usr/local/opt/sqlite/bin:$PATH"' >> ~/.bash_profile

For compilers to find sqlite you may need to set:
  export LDFLAGS="-L/usr/local/opt/sqlite/lib"
  export CPPFLAGS="-I/usr/local/opt/sqlite/include"

python
Python has been installed as
  /usr/local/bin/python3

Unversioned symlinks `python`, `python-config`, `pip` etc. pointing to
`python3`, `python3-config`, `pip3` etc., respectively, have been installed into
  /usr/local/opt/python/libexec/bin

You can install Python packages with
  pip3 install <package>
They will install into the site-package directory
  /usr/local/lib/python3.7/site-packages

See: https://docs.brew.sh/Homebrew-and-Python
Carolines-Air:~ caroline$`

Answer 1

我建议不要安装python3，而是安装pyenv。

brew install pyenv

然后按照（在.bash_profile 或.zshrc 中设置路径变量）中的说明进行操作：

pyenv init

那么简单：

pyenv install 3.8.0
pyenv global 3.8.0

你可以走了！然后在任何地方使用 Python：

python