This Python script cannot open by a editor?

[rxjwg98 at gmail.com]

Hi,

I am learning a Python Tool from web: 
http://www.ohwr.org/projects/hdl-make/wiki/Quick-start-new

I download the program to Ubuntu 12.04. I find that in the folder it is shown as
hdlmake-v1.0, 37.8 KB Python Script. I remember that script file can be loaded
to an editor to read its content. But, when I open it by double click, it is
shown as like binary file in GEDIT. 

What is the reason of this?

A general Python file has .py extension, and can be edited. Is it right?

Thanks