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

Defining the ShapeEditor's applications


We now have a Django project for our overall ShapeEditor system. We next need to break down our project into several related applications, following Django's design philosophy of having applications be small and relatively self-contained. Looking back at our design for the overall project, we can see several possible candidates for breaking the functionality into separate applications:

  • Importing and exporting shapefiles

  • Selecting features

  • Editing features

  • The Tile Map Server

Let's choose some names for our applications, keeping them short and to the point:

  • importer

  • exporter

  • selector

  • editor

  • tms

We will define one more application, which we'll called shared, to hold the database models and Python modules that are shared across these applications.For example, we might have a module named attributeReader.py that is needed by the importer and editor applications. We'll place this into the shared application to make it clear that this code is designed to be used elsewhere...