Book Image

Python Geospatial Development - Second Edition - Second Edition

By : Erik Westra
Book Image

Python Geospatial Development - Second Edition - Second Edition

By: Erik Westra

Overview of this book

Geospatial development links your data to places on the Earth's surface. Writing geospatial programs involves tasks such as grouping data by location, storing and analyzing large amounts of spatial information, performing complex geospatial calculations, and drawing colorful interactive maps. In order to do this well, you'll need appropriate tools and techniques, as well as a thorough understanding of geospatial concepts such as map projections, datums and coordinate systems. Python Geospatial Development - Second Edition teaches you everything you need to know about writing geospatial applications using Python. No prior knowledge of geospatial concepts, tools or techniques is required. The book guides you through the process of installing and using various toolkits, obtaining geospatial data for use in your programs, and building complete and sophisticated geospatial applications in Python. Python Geospatial Development teaches you everything you need to know about writing geospatial applications using Python. No prior knowledge of geospatial concepts, tools or techniques is required. The book guides you through the process of installing and using various toolkits, obtaining geospatial data for use in your programs, and building complete and sophisticated geospatial applications in Python. This book provides an overview of the major geospatial concepts, data sources and toolkits. It teaches you how to store and access spatial data using Python, how to perform a range of spatial calculations, and how to store spatial data in a database. Because maps are such an important aspect of geospatial programming, the book teaches you how to build your own “slippy map” interface within a web application, and finishes with the detailed construction of a geospatial data editor using Geodjango. Whether you want to write quick utilities to solve spatial problems, or develop sophisticated web applications based around maps and geospatial data, this book includes everything you need to know.
Table of Contents (18 chapters)
Python Geospatial Development
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Implementing the DISTAL application


Now that we have the data, we can start to implement the DISTAL application itself. To keep things simple, we will use CGI scripts to implement the user interface.

Note

CGI scripts aren't the only way we could implement the DISTAL application. Other possible approaches include using web application frameworks such as TurboGears or Django, using AJAX to write your own dynamic web application, using CherryPy (http://cherrypy.org) or even using tools such as Pyjamas (http://pyjs.org) to compile Python code into JavaScript. All of these approaches, however, are more complicated than CGI, and we will be making use of CGI scripts in this chapter to keep the code as straightforward as possible.

Let's take a look at how our CGI scripts will implement the DISTAL application's workflow:

As you can see, there are three separate CGI scripts, selectCountry.py, selectArea.py, and showResults.py, each implementing a distinct part of the DISTAL application.

Tip

What is a CGI...