1. Installation:
Now it is a stable release so if you want to install it in your system you can do it else try it in a virtual environment. To install it in yur system it requires su access.
To install the script do this
Option 1 : Install via pip ::
$ sudo pip install pysub-dl
Option 2 : If you have downloaded the source
$ sudo python setup.py install
Do not forget to upgrade it after a week interval I am modifying so many things very frequently ::
$ sudo pip install...