Python. How to extract data from .csv and perform calculations on data from tables?

Question

Python

Hello.
Just started learning Python. Knowledge is not enough, but the excitement is incredible. It helps and hinders at the same time.
Tell me, what tools can be used to extract data from .csv files and perform calculations on them? Tried pandas, killed all weekend learning this library, but I didn't understand how to use fetched data in calculations: query using .loc gives "dirty answer":
3 1
Name: London, dtype: int64

I would be very grateful!