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

Exercises


If you are interested in exploring the techniques used in this chapter further, you might like to challenge yourself with the following tasks:

  • Change the "Calculate Bounding Box" calculation to exclude outlying islands.

    Tip

    Hint

    You can split each country's MultiPolygon into individual Polygon objects, and then check the area of each polygon to exclude those which are smaller than a given total value.

  • Use the World Borders Dataset to create a new shapefile, where each country is represented by a single "Point" geometry containing the geographical center of each country.

    Tip

    Hint

    You can start with the country bounding boxes we calculated earlier, and then calculate the midpoint using:

    midLat = (minLat + maxLat) / 2
    midLong = (minLong + maxLong) / 2

    For an extra challenge, you could use Shapely's centroid() method to calculate a more accurate representation of each country's center. To do this, you would have to convert the country's outline into a Shapely geometry, calculate the centroid...