Now that we understand how to interact with ArcToolbox tools using ArcPy, and we have also covered using Python to create functions and import modules, we have a basic understanding of how to improve GIS workflows using Python. In this chapter we will cover data cursors and the Data Access module, introduced in 10.1. These data access cursors are a vast improvement on the cursors used in the arcgisscripting module (the precursor to ArcPy) and in earlier versions of ArcPy. Not only can the cursors search data, as we have seen, but they can update data using the Update Cursors and can add new rows of data using the Insert Cursor.

Data cursors are used to access data records contained within data tables, using a row by row iterative approach. The concept was borrowed from relational databases, where data cursors are used to extract data from tables returned from a SQL expression. Cursors are used to search for data, but...