Introspecting a Book
The xlrd.Book object returned by open_workbook contains all information to do with
the workbook and can be used to retrieve individual sheets within the workbook.
The nsheets attribute is an integer containing the number of sheets in the workbook.
This attribute, in combination with the sheet_by_index method, is the most common
way of retrieving individual sheets.
The sheet_names method returns a list of unicodes containing the names of all sheets in
the workbook. Individual sheets can be retrieved using these names by way of the
sheet_by_name function.
The results of the sheets method can be iterated over to retrieve each of the sheets in the
workbook.
The following example demonstrates these methods and attributes: