Amongst all the processing algorithms already available in QGIS, sometimes the one thing you need is missing. This happened not a long time ago, when we were asked to find a way to continuously visualise traffic on the Swiss motorway network (polylines) using frequently measured traffic volumes from discrete measurement Read more…
While porting a plugin to QGIS3 I decided to also move all it’s threading infrastructure to QgsTasks. Here three possible variants to implement this.the first uses the static method QgsTask.fromFunction and is simpler to use. A great quick solution. If you want need control you can look at the second Read more…
The Release of QGIS 3.0 was a great success and with the first LTR (3.4) scheduled for release this fall, it is now the perfect time to port your plugins to the new API. QGIS 3.0 is the first major release since September 2013 when QGIS 2.0 was released. During Read more…
Lately, I have been confronted with the need of translating Interlis files (from French to German) to use queries originally developed for German data. I decided to create an automated convertor for Interlis (version 1) Transfer Format files (.ITF) based on the existing cadastral data model from the Swiss confederation Read more…
Recently there have been some questions and discussions about python based expression functions and how parameters like usesGeometry need to be used. So I thought I’d quickly write down how this works. There is some intelligence If the geometry or a column is passed in as a parameter you do not Read more…
Here an example on how to work with threads in a consistent and clean manner in QGIS python plugins
Behind the scenes a lot has happened to get ready for Qt5 and Python3. On the same codebase that is becoming the next release QGIS 2.16. This is really a great thing since we can focus work on a single master branch and I’m very happy that we got so Read more…
Processing just got a new testing framework to improve the long-term stability of this important plugin. And you can help to improve it, even if you are not a software developer! This is yet another piece in our never-stopping crusade to improve the stability and quality of the best desktop GIS on Read more…
PyQGIS now supports a nice new addition for handling edit sessions in layers. This way, changes get committed automatically at the end of a successful (python) edit session.
with edit(layer):
do your changes here()
This post discusses how to improve the performance of pyqgis code which updates a lot of features by a factor of more than 10.