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

Playing with the admin system


The built-in admin application is enabled by default in new Django projects. Before we can use it, however, we need to register the various database models we want it to support. To do this, edit the admin.py module within the shapeEditor/shared directory, and enter the following into this file:

from django.contrib.gis import admin
from shapeEditor.shared.models import *

admin.site.register(Shapefile, admin.ModelAdmin)
admin.site.register(Feature, admin.GeoModelAdmin)
admin.site.register(Attribute, admin.ModelAdmin)
admin.site.register(AttributeValue, admin.ModelAdmin)

The ModelAdmin class tells Django how to display the model within the admin interface. Notice that we use the GeoModelAdmin class for the Feature class. Because the Feature object includes geometry fields, using the GeoModelAdmin class allows the admin interface to edit these geometry fields using a slippy map. We'll see how this works shortly.

Now that the admin module has been configured, let...