i want to know when should make scaling on data
@AhmedAdel, I think you should go through this article once
Practical Guide on Data Preprocessing in Python using Scikit Learn https://www.analyticsvidhya.com/blog/2016/07/practical-guide-data-preprocessing-python-scikit-learn/
This will give you a practical overview of feature scaling and when do you use it.
Post back any follow up queries you may have here!