how to detect the character encoding in a web page ?

[iMath]

在 2012年12月24日星期一UTC+8上午8时34分47秒，iMath写道：
> how to detect the character encoding  in a web page ?
> 
> such as this page 
> 
> 
> 
> http://python.org/

but how to let python do it for you ?

such as this page 

http://python.org/ 

how to  detect the character encoding in this web page by python ?