MacBook使用pip安装JupyterLab
1、pip install jupyterlab或者pip3 install jupyterlab
2、安装完毕后，输入jupyter-lab，但是报错了！
-bash: jupyter-lab: command not found
别慌，先找安装的文件在哪儿！使用下面的语句查找安装的地方
mdfind -name jupyter
我的结果为（删除部分，保留/bin部分，因为这里存的是命令）
/Library/Frameworks/Python.framework/Versions/3.7/bin/jupyter-console
/Library/Frameworks/Python.framework/Versions/3.7/bin/jupyter-qtconsole
/Library/Frameworks/Python.framework/Versions/3.7/bin/jupyter-serverextension
/Library/Frameworks/Python.framework/Versions/3.7/bin/jupyter-notebook
/Library/Frameworks/Python.framework/Versions/3.7/bin/jupyter-nbextension
/Library/Frameworks/Python.framework/Versions/3.7/bin/jupyter-bundlerextension
/Library/Frameworks/Python.framework/Versions/3.7/bin/jupyter-nbconvert
/Library/Frameworks/Python.framework/Versions/3.7/bin/jupyter-trust
/Library/Frameworks/Python.framework/Versions/3.7/bin/jupyter-run
/Library/Frameworks/Python.framework/Versions/3.7/bin/jupyter-kernelspec
/Library/Frameworks/Python.framework/Versions/3.7/bin/jupyter-kernel
/Library/Frameworks/Python.framework/Versions/3.7/bin/jupyter-troubleshoot
/Library/Frameworks/Python.framework/Versions/3.7/bin/jupyter-migrate
/Library/Frameworks/Python.framework/Versions/3.7/bin/jupyter
可以看到上面的结果，文件路径在/Library/Frameworks/Python.framework/Versions/3.7/bin里面，于是打开上诉文件件，找到jupyter-lab，双击运行，会发现，哎，出来了。
3、可以看出找不到命令还需要配置环境变量，于是vi ~/.bash_profile
1、JUPYTER=/Library/Frameworks/Python.framework/Versions/3.7
2、PATH=原来的路径:$JUPYTER/bin
3、export JUPYTER
4、export PATH
最后，source ./.bash_profile，使刚才的文件生效，echo $PATH查看是否有新添加进去的路径。
4、jupyter-lab，就ok啦！