Book Image

Python Geospatial Development - Third Edition

By : Erik Westra
Book Image

Python Geospatial Development - Third Edition

By: Erik Westra

Overview of this book

Geospatial development links your data to locations on the surface of the Earth. 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. This book provides an overview of the major geospatial concepts, data sources, and toolkits. It starts by showing 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. Further on, 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 the GeoDjango framework. By the end of this book, you will be able to confidently use Python to write your own geospatial applications ranging from quick, one-off utilities to sophisticated web-based applications using maps and other geospatial data.
Table of Contents (20 chapters)
Python Geospatial Development Third Edition
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Creating the shared application


The shapeEditor.shared application will hold the core database tables and Python modules we use throughout the system. Let's go ahead and create this application now. Use the cd command to change the current directory to the top-level shapeEditor directory and type the following:

python manage.py startapp shared

This will create a new Python package named shared that will hold the contents of the shared app. Note that, by default, a new application is placed in the topmost shapeEditor directory. This means you can import this application into your Python program like this:

import shared

Django's conventions say that applications in the topmost directory (or anywhere else in your Python path) are intended to be reusable—that is, you can take that application and use it in a different project. The applications we're defining here aren't like that; they can only work as part of the shapeEditor project, and we would like to be able to import them like this:

import...