我用brew brew upgrade升级了过时的软件包,但是现在我发现以前使用的pip3命令(Python 3的pip)消失了.我的Python 3.6安装仍然存在：
cls@clsmba > python3
Python 3.6.5 (default, Mar 30 2018, 06:42:10)
[GCC 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.39.2)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>>
> pip指向适用于Python 2.7的pip：
cls@clsmba ~> pip --version
pip 9.0.3 from /usr/local/lib/python2.7/site-packages (python 2.7)
cls@clsmba ~> pip2 --version
pip 9.0.3 from /usr/local/lib/python2.7/site-packages (python 2.7)
pip3.5似乎是旧版Python 3的遗留物：
cls@clsmba ~> pip3.5
Failed to execute process '/usr/local/bin/pip3.5'. Reason:
The file '/usr/local/bin/pip3.5' specified the interpreter '/usr/local/opt/python3/bin/python3.5', which is not an executable command.
我尝试使用get-pip.py找回命令,但这没有用：
cls@clsmba ~> python3 get-pip.py
Requirement already up-to-date: pip in /usr/local/lib/python3.6/site-packages
我现在该怎么做才能以干净的方式取回命令？
使用brew重新安装python重新安装未安装pip.另外,请注意错误消息：
cls@clsmba > brew reinstall python
==> Reinstalling python
==> Installing dependencies for python: sqlite
==> Installing python dependency: sqlite
==> Downloading https://homebrew.bintray.com/bottles/sqlite-3.23.1.sierra.bottle.tar.gz
==> Downloading from https://akamai.bintray.com/75/75bf05c73a9b51101ea166742eb9baf285eda857fd98ea1d50a3abf0d81bd978?__gda__=exp=1523530592~hmac=ae4fc4056ff461c4fc3ca75983cd0f22c231e084312090e6c484aa59b02d3c1f&response-content-disposition=attachment%3Bfilename%3D%22sqlite-3.23.1.sierra.bottle.tar.gz%22&response-content-type=application%2Fgzip&requestInfo=U2FsdGVkX1-3IGgcJJtJX59zX8HP5dbhO9NFlYr07n9KOgP7AOcaoTM4pAOrLWqfH9MzbvCoUoNWKvWGRelKsrku6Kulv8WBBKAT7jGnTKBaYlEQpp1oEnHgh5nU-WVdBxk
######################################################################## 100.0%
==> Pouring sqlite-3.23.1.sierra.bottle.tar.gz
==> Caveats
This formula is keg-only, which means it was not symlinked into /usr/local,
because macOS provides an older sqlite3.
If you need to have this software first in your PATH run:
echo 'export PATH="/usr/local/opt/sqlite/bin:$PATH"' >> ~/.bash_profile
For compilers to find this software you may need to set:
LDFLAGS: -L/usr/local/opt/sqlite/lib
CPPFLAGS: -I/usr/local/opt/sqlite/include
For pkg-config to find this software you may need to set:
PKG_CONFIG_PATH: /usr/local/opt/sqlite/lib/pkgconfig
==> Summary