python tip

Sometimes, you'll prefer to transform one level of the index (like email_provider) into the columns of your data frame. That's exactly what unstack() does. It's better to explain this with an example. So, let's unstack our code above:

# Moving 'Mail providers' to the column names
clients.groupby('state')['email_provider'].value_counts().unstack().fillna(0)

As you can see, the values for the email service providers are now the columns of our data frame. Now it's time to move on to some other general Python tricks beyond pandas.