The CSV, XLRD, and XLWT modules

The csv, xlrd, and xlwt modules are used to read and write data spreadsheets. They can be very useful for extracting data from the spreadsheets and converting them into data for GIS analysis, or for writing out analysis results as spreadsheets when an analysis is complete. The csv module (which creates text file spreadsheets using text delimiters like commas) is a built-in module, while xlrd and xlwt (which read and write Excel files respectively) are not part of the standard library, but are installed along with ArcGIS and Python 2.7.