One of the very first thing you should learn is selecting the relevant data quickly and effectively from a dataframe. This is a very basic step that is needed in almost any data operation that you will run.
For example:
Say, you are a data scientist at Amazon. During the time of New Year, your supervisor asked you to give a discount of 50% for all the electronic items available at Amazon.
You will never want to go to each electronic item and assign a discount of 50% to each of them. This would be a lot of time consuming task. Instead you would want to select all the items that falls under the category ‘electronics’ and then give all the item a discount of 50% at one go. So easy, right? This is where you will need indexing, selecting and assigning data in a dataframe.
