It is possible to do the same things in Pandas is many different ways. It is good to have this flexibility, but it is confusing for new users. On top of that the bracket operator ([) is overloaded in many ways.

Things started to make sense after I read a very good book on Pandas[1]. Reading a book is better than reading blog posts, because it is consistent. In contrast, reading small tutorials for every little thing is confusing, because every blog post is using a different way to do the same thing.

[1] https://github.com/jakevdp/PythonDataScienceHandbook