Pulkit, There are many online trainings and institutions available to learn python such as DataCamp, Coursera, Edureka, Udacity, etc. Since you are from a different domain, it will take time to learn but practice makes a man perfect.
Follow the below steps:
1. Learn python step by step either training or self-paced along with video tutorials so that you will cover in depth and breadth of a topic.
2. Practice and understand every code you learn and work on it.
3. Post your doubts in any python community where professionals or experienced people would help you answer your doubts.
4. Clear your doubts on the same day. Do not drag the topic or doubt later.
5. Work and practice on some python real examples or sample projects.
6. Check out challenges or any solved challenges and try to solve such as problems in hackerrank or hacker earth.
Hope it helps!