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

Working with GIS data manually


Let's take a brief look at the process of working with GIS data manually. Before we can begin, there are two things you need to do:

  • Obtain some GIS data

  • Install the GDAL Python library so that you can read the necessary data files

Let's use the US Census Bureau's website to download a set of vector maps for the various US states. The main site for obtaining GIS data from the US Census Bureau can be found at:

http://www.census.gov/geo/www/tiger

To make things simpler though, let's bypass the website and directly download the file we need from the following link:

http://www2.census.gov/geo/tiger/TIGER2012/STATE/tl_2012_us_state.zip

The resulting file, tl_2009_us_state.zip, should be a ZIP-format archive. After uncompressing the archive, you should have the following files:

  • tl_2012_us_state.dbf

  • tl_2012_us_state.prj

  • tl_2012_us_state.shp

  • tl_2012_us_state.shp.xml

  • tl_2012_us_state.shx

These files make up a Shapefile containing the outlines of all the US states. Place these files...