Hands-On Data Analysis with Pandas

Data transformation

Frequently, we will reach the data transformation stage after some initial data cleaning, but it is entirely possible that our dataset is unusable in its current shape, and we must restructure it before attempting to do any data cleaning. In data transformation, we focus on changing our data's structure to facilitate our downstream analyses; this usually involves changing which data goes along the rows and which goes down the columns.

Most data we will find is either in a wide format or a long format; each of these formats has its merits, and it's important to know which one we will need for our analysis. Often, people will record and present data in the wide format, but there are certain visualizations that require the ...