Python 3.6 安装 Flask

pip install flask

如果你跟我一样在安装MarkupSafe报错的话，请安装MarkupSafe的轮子（https://www.lfd.uci.edu/~gohlke/pythonlibs/#markupsafe）下载对应的轮子文件后，pip install MarkupSafe-1.0-cp36-cp36m-win32.whl我的是MarkupSafe-1.0-cp36-cp36m-win32，请将这个换成你下载的文件名。
Finish~
在命令行输入flask，flask就可以看到flask 已经成功安装了。

Usage: flask [OPTIONS] COMMAND [ARGS]...

This shell command acts as general utility script for Flask applications.

It loads the application configured (through the FLASK_APP environment
variable) and then provides commands either provided by the application or
Flask itself.

The most useful commands are the "run" and "shell" command.

Example usage:

set FLASK_APP=hello.py
set FLASK_DEBUG=1
flask run

Options:
--version  Show the flask version
--help     Show this message and exit.

Commands:
run    Runs a development server.
shell  Runs a shell in the app context.