Selecting the data in specific columns of a DataFrame is performed by using the  operator. This differs from a Series, where  specified rows. The  operator can be passed either a single object or a list of objects representing the columns to retrieve.
The following retrieves the column with the name 'Sector':
When a single column is retrieved from a DataFrame, the result is a Series:
Multiple columns can be retrieved by specifying a list of column names:
Since this has multiple columns, the result ...