Book Image

QGIS Python Programming Cookbook, Second Edition - Second Edition

By : Joel Lawhead
Book Image

QGIS Python Programming Cookbook, Second Edition - Second Edition

By: Joel Lawhead

Overview of this book

QGIS is a desktop geographic information system that facilitates data viewing, editing, and analysis. Paired with the most efficient scripting language—Python, we can write effective scripts that extend the core functionality of QGIS. Based on version QGIS 2.18, this book will teach you how to write Python code that works with spatial data to automate geoprocessing tasks in QGIS. It will cover topics such as querying and editing vector data and using raster data. You will also learn to create, edit, and optimize a vector layer for faster queries, reproject a vector layer, reduce the number of vertices in a vector layer without losing critical data, and convert a raster to a vector. Following this, you will work through recipes that will help you compose static maps, create heavily customized maps, and add specialized labels and annotations. As well as this, we’ll also share a few tips and tricks based on different aspects of QGIS.
Table of Contents (16 chapters)
QGIS Python Programming Cookbook - Second Edition
About the Author
About the Reviewer
Customer Feedback

Chapter 9. Other Tips and Tricks

In this chapter, we will cover the following:

  • Creating tiles from a QGIS map

  • Adding a layer to

  • Rendering map layers based on rules

  • Creating a layer-definition file

  • Using NULL values in PyQGIS

  • Using generators for layer queries

  • Using alpha values to show data density

  • Using the __geo_interface__ protocol

  • Getting the output file names from processing algorithms

  • Generating points along a line

  • Using expression-based labels

  • Creating dynamic forms in QGIS

  • Calculating the length for all selected lines

  • Using a different status bar CRS than the map

  • Creating HTML labels in QGIS

  • Using OpenStreetMap points of interest in QGIS

  • Changing the QGIS web proxy

  • Running QGIS scripts as scheduled tasks

  • Visualizing data in 3D with WebGL

  • Visualizing data on a globe

  • Make a globe-like azimuthal orthographic projection

  • Animating a layer