mac OSX 10.14.4安装jupyter

1.本文假设读者已经安装python3以及pip3(安装python3后会自带)
2.安装指令

$ pip3 install --user jupyter

在等待过程中会出现很多看起来不太舒服的提示（看文字颜色就觉得异常），异常提示如下

  The scripts jupyter, jupyter-migrate and jupyter-troubleshoot are installed in '/Users/chenhao/Library/Python/3.6/bin' which is not on PATH.
  Consider adding this directory to PATH or, if you prefer to suppress this warning, use --no-warn-script-location.
  The scripts jupyter-kernel, jupyter-kernelspec and jupyter-run are installed in '/Users/chenhao/Library/Python/3.6/bin' which is not on PATH.
  Consider adding this directory to PATH or, if you prefer to suppress this warning, use --no-warn-script-location.
  The script jsonschema is installed in '/Users/chenhao/Library/Python/3.6/bin' which is not on PATH.
  Consider adding this directory to PATH or, if you prefer to suppress this warning, use --no-warn-script-location.
  The script jupyter-trust is installed in '/Users/chenhao/Library/Python/3.6/bin' which is not on PATH.
  Consider adding this directory to PATH or, if you prefer to suppress this warning, use --no-warn-script-location.
  The script pygmentize is installed in '/Users/chenhao/Library/Python/3.6/bin' which is not on PATH.
  Consider adding this directory to PATH or, if you prefer to suppress this warning, use --no-warn-script-location.
  The script jupyter-nbconvert is installed in '/Users/chenhao/Library/Python/3.6/bin' which is not on PATH.
  Consider adding this directory to PATH or, if you prefer to suppress this warning, use --no-warn-script-location.
  The scripts iptest, iptest3, ipython and ipython3 are installed in '/Users/chenhao/Library/Python/3.6/bin' which is not on PATH.
  Consider adding this directory to PATH or, if you prefer to suppress this warning, use --no-warn-script-location.
  The scripts jupyter-bundlerextension, jupyter-nbextension, jupyter-notebook and jupyter-serverextension are installed in '/Users/chenhao/Library/Python/3.6/bin' which is not on PATH.
  Consider adding this directory to PATH or, if you prefer to suppress this warning, use --no-warn-script-location.
  The script jupyter-console is installed in '/Users/chenhao/Library/Python/3.6/bin' which is not on PATH.
  Consider adding this directory to PATH or, if you prefer to suppress this warning, use --no-warn-script-location.

3.等待结束之后，我们测试一下，看能不能用

$ jupyter notebook --help

结果提示，果然不能用

-bash: jupyter: command not found

出现这个原因是因为环境变量未配置，所以我们配置一下环境变量
3.我们进入环境变量的配置文件

$ vim ~/.bash_profile

然后在文件里添加以下配置

export PATH=/Users/chenhao/Library/Python/3.6/bin:$PATH

这里注意替换成你的jupyter的安装目录，也就是本文的第二个代码框里显示的路径(每个人不一样)，然后保存退出。
4.接下来使配置文件生效，并且再次测试一下

$ source ~/.bash_profile  #使配置文件生效
$ jupyter notebook --help  #测试，有一大堆东西跳出来说明成功了