Draw anti-alias circle at give point with specified radius using OpenGL Core profile

In modern opengl (core profile), there are a lot of tutorials on how to draw a circle using fragment shader,
but most of lack of source code and only show how to draw at (0,0).
This code piece draw circle at given center point with specified radius.
pyopengl implementation is at github:
https://github.com/stonewell/code-snippets/tree/master/opengl%5Fcircle