Python bindings for QGIS.

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Calling PyQGIS functions from external editors (Linux)

Is it possible to integrate external Python editors (such as KDevelop) with QGIS, so that it would be possible to run functions in qgis.core, qgis.utils etc. outside of the QGIS Python Console? ...
7
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2answers
192 views

Why do I get different results from PyQGIS feature.geometry().type()?

On the python console in QGIS what is the difference between the following two code snippets (activeLayer is a polygon layer): # 1) iface.activeLayer().selectedFeatures()[0].geometry().type() >>...
7
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1answer
158 views

Filling fields with conditional clauses

I have four fields in my shapefile. I would like to fill only one of them (cell of attribute table) and automatically after to write one cell the others one will be filled by conditional clause. I ...
7
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1answer
430 views

How to exit QGIS after running a python script?

I would like to run a python script via qgis --code myscript.py and then immediately exit. I'm using iface.actionExit().trigger(), which kills QGIS when I run it from the python console, but not when ...
7
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2answers
586 views

How to load a raster layer at the top of the QGIS ToC?

The following code inserts my new_layer just above the active layer in the QGIS ToC. new_layer = iface.addRasterLayer(...) Instead, I'd like my new_layer to be inserted at the top of the QGIS ToC. ...
7
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1answer
89 views

Compute zonal statistics for portion of polygons

I am working with a shape file containing the district polygons of the political map of India and a raster file containing the elevation data of the same country. My goal is to compute the average and ...
7
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1answer
1k views

Calling GRASS modules in pyQGIS?

I wish to use a Grass module (v.to.db) in QGis, without the grass toolbox. I tried with the Python console, but to no avail : Using Sextante plugin but obviously it didn't know all the grass ...
7
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1answer
97 views

How to index large VRT files in QGIS?

I have a large number of small tiles merged into a single VRT. The rasters are only viewed at large scale, so only a few of them are visible at the same time. The map refresh in qgis is slowing down ...
7
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228 views

Unable to load .gpx file from Python Console

I'm trying to create a plugin which will extract the gpx files and load them onto the active layer window in QGIS. While I'm able to load it using the QGIS GUI from Layer>New Vector Layer, I'm not ...
7
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1answer
361 views

Is it possible to use memory layers in QGIS processing algorithms?

I am building a QGIS plugin that connects to a MySQL database in the local network, and then adds a subset of one of the tables to an in-memory layer; the subset is based on data currency (only taking ...
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85 views

Development of a plugin which depends on an external Python library

I'm developing a Python plugin, the target is integrating into QGIS the functionalities of a PyPI Python library called 'elevation'. Is there an OS independent way of installing external Python ...
6
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3answers
322 views

Is there a way of labeling the number of points with the same coordinates?

After reading through the following question (which is kinda related but not quite what I need): How can I show points on the same coordinate as e.g. a bigger symbol in QGIS? I found out that there ...
6
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3answers
3k views

how to for loop a folder to batch clip rasters by polygon using python and QGIS

I am using python and QGIS 2.0. I am trying to clip rasters in a folder by one polygon feature. It's the first time for me using (let's say) "PyQGIS", I was used to arcpy before. Anyway, I don't get ...
6
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1answer
2k views

How to identify and highlight features programmatically?

In QGIS there is an option to select features of a selected layer using a "identify feature" tool. Then the feature get highlighted in a different color and attribute dialog is poping up. like that i ...
6
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2answers
4k views

How can i obtain the data of one selected feature in QGIS using python?

I have a problem / question regarding python and QGIS. Is it, and yes how, possible to get the data of one selected feature in QGIS using python? In my example I have a layer which shows some parcels ...
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4answers
3k views

How to find the polygon inside which a point lies?

I have a layer with polygonal features. Each feature has attributes and values. I also have a list of co-ordinates and I would like to know which feature (or polygon) the co-ordinates lie in. Could ...
6
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1answer
2k views

QGIS Zoom from python console

What are the commands to apply all types of zoom (full, on selected layer, etc.) in python console? I'm searching both on pyqgis cookbook and API documentantion, but I'm not finding anything ...
6
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2answers
311 views

Skeletonize vectors in QGIS/Python

I am trying to find a tool to create a skeleton of a large vector dataset using QGIS and its bundle. It should be directly programmatically callable through Python or commandline (QGIS, GRASS, OGR etc....
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2answers
2k views

How can I access `processing` with Python?

I want to access the explode lines function in Python outside of QGIS from a standalone script. What module do I have to load in order to use it? How can I access processing? from qgis.core import * ...
6
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1answer
147 views

How to close/remove QGIS welcome page (recent projects) with Python?

Is it possible to close the QGIS welcome page with Python? I have a permanently docked Python plugin, that uses showRubberBand to directly write into map canvas. Therefor I have to close/remove the ...
6
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2answers
2k views

How to load memory output from QGIS processing?

Many processing algorithms have an option to save output as memory. If ran from toolbox, this works fine, because you can tick the "Open output file after running algorithm" box. Looking at the ...
6
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1answer
2k views

How to zoom to a selected feature with pyQGIS

I want to create a function that selects a feature and zooms to it (similar in QGIS). Therefore there is following function: QgsMapLayerRegistry.instance().addMapLayer(self.vlayer) def zoomTo(self): ...
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3answers
865 views

How do I specify the position, style and units of the ScaleBar in pyqgis?

I would like to add a scale bar to my composition using the python console and then export it to a raster image. I am following the MapRendering tutorial with the "output using map composer " approach ...
6
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1answer
3k views

Using in-memory vector layer with QGIS processing / SEXTANTE

I'm trying to run the qgis:clip algorithm from console, but am getting an error when using an in-memory layer as the overlay parameter. Is this to be expected, or am I doing something wrong? Code: ...
6
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1answer
895 views

How do I allow users to select features with the mouse?

I am using PyQGis API to create a custom application. How do I allow users to select features with the mouse? Is there a mapTool for this? Surely with a product as powerful as QGis there must be. ...
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3answers
178 views

Counting number of vertices of object on vector layer PyQGIS

First of all, I want to say that I know that similar issue was raised before, but it didn't provide satisfying solution. I need to get the number of vertices of every object on vector line layer. ...
6
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2answers
215 views

Adding all Binary Rasters in a Directory Using Raster Calculator in a Standalone Python Script

I have a directory with binary raster files (1 band only) which I need to add in a standalone python script. The problem is the rasters have different number of rows and columns and different ...
6
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1answer
778 views

QGIS Processing Progress

I have been developing a python plugin that uses Processing algorithm for raster calculations. I want to support the gui with progress bar. How can i connect Processing job to progress bar? I found ...
6
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3answers
1k views

How do I set layer transparency in QGIS 2.0 with Python?

I have a raster layer loaded in QGIS and I'd like to be able to set its transparency via the Python console. I'm new to the API and have not been able to find out how to do this. Any help would be ...
6
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2answers
254 views

Start QGIS with virtualenv Python

is there any means of telling QGIS to use a different Python installation than the default, system-wide one? E.g. use some virtualenv Python /myvirtualenv/bin/python instead of /usr/bin/python? ...
6
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1answer
422 views

Efficiently generate Voronoi layers in qgis via Python

The following python commands both appear to function when called in qgis 2.6 to generate Voronoi diagrams: processing.runalg("qgis:voronoipolygons", pointLayer, 1, None) processing.runalg("grass:v....
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1answer
391 views

How to get the file name of current style using PyQGIS?

I get the name of the current style file using layer.styleURI(). Then, I change the style file using layer.loadNamedStyle(different_filename). However, when I call layer.styleURI() again, it ...
6
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1answer
62 views

QGIS crashes when doing a rollback after modifying values of an user-added feature with pyQGIS

I'm developing an addon for QGIS that needs to assign a UUID to any feature as soon as it is added to the layer. I'm using the featureAdded signal to write the UUID in the corresponding field of the ...
6
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1answer
171 views

How to use third-party package in a QGIS plugin?

I'm developing a QGIS plugin and I would like to use arrow or requests packages as I'm used to manipulate dates and REST APIs. QGIS does not come with these packages (at less arrow), so when I try to ...
6
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1answer
419 views

Getting QGIS python modules to work from PyScripter in Windows 10?

Been trying lots of "solutions" from net research but nothing seems to work. I have the current versions of QGIS from OSGEO and PyScripter 2.5 Based on one of the solutions I tried... import sys ...
6
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1answer
4k views

Problem with import qgis.core when writing a stand-alone PyQGIS script

I am trying to write a stand alone python script in windows 7 that uses qgis.core and various other qgis libraries. I have found an old question on this subject here: How to write standalone Python ...
6
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1answer
1k views

How to write vector layer to csv file with geometry by PYTHON?

I use Python try to write vector layer file to csv file with this code QgsVectorFileWriter.writeAsVectorFormat(mylayer, r'c:\temp\xyz.csv', "utf-8", None, "CSV") It can export to xyz.csv but only ...
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0answers
123 views

Using memory layer as input and/or output with runalg?

Can a memory layer be used as an input and/or output with runalg? With runandload I get this to work: processing.runandload("qgis:mergevectorlayers","memory:bufferOne", "memory:bufferTwo", r"memory:...
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385 views

Performing buffering and intersection with script in PyQGIS [closed]

I wrote a script that performs the intersection of two layers: The first Layer -> layer1, represents the rivers The second Layer -> layer2, represents a set of circular dots distributed in a ...
5
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2answers
161 views

Retrieve available PostGIS connections in PyQGIS

Can I retrieve the available connections to PostGIS databases in PyQGIS? I would like to provide a list of available db-connections, and subsequently a list of tables within the ui of my plugin. I ...
5
votes
1answer
1k views

How to programmatically associate a layer with a custom UI?

I know it is possible to associate a layer with a custom UI for editing feature attributes using the QGIS interface. But is this possible with Python? This link shows how to achieve the result ...
5
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2answers
2k views

How to automatically reload raster layers if source is changed in QGIS?

How to automatically reloaded raster layer if source is changed? (The path is the same but inside source file are changes) I use: qgis.utils.iface.mapCanvas().refresh() but layer not refresh. # ...
5
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3answers
4k views

How can I specify the CRS of a raster layer in pyqgis?

I manipulating netcdf raster data from the QGIS python console. The metadata of my netcdf file does not provide the Reference system. However I know it is 'EPSG:4326' I am writing a python script to ...
5
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2answers
222 views

Field Editor with Python: select by attribute & open table (QGIS)

I want to search on number values (>, = etc.) within a column and open table for the selected ones. It's an easy task within field calculator, but I want to see how it's build up with the python ...
5
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1answer
2k views

How to delete selected features in Qgis using Python

I have a shape file with only one field DN. I would like to delete all features which does not have specific value of the field. Let say the DN can be 1,2 or 3. So far I was able to find out how to ...
5
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1answer
585 views

How to begin with tool development for GRASS gis or QGIS GRASS

I wanted to begin with customized tool development in Grass GIS or QGIS grass. How should i begin in to develop the tool. I search a lot in google search engine for begin with tool development in ...
5
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2answers
3k views

How to show a message box in QGIS?

I am starting to develop a plugin for Qgis using python, which i am very new at, and would like to view some results of variables by displaying a message in QGIS. How can I do this?
5
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1answer
3k views

pyqgis: How to get features of selected geometries

I wonder if anybody could provide an example how to get the attributes of selected Features? I tried the folowing Code in the python Console - but I'm stuck at the point where I'd like to get the ...
5
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2answers
216 views

How to find disconnected islands in a road network layer, using QGIS

I have a road network layer that can't route from one side of the layer to the other. Topologically, there is no connectivity between the start and end nodes, probably due to missing links. This ...
5
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2answers
812 views

How to add a legend to a canvas in a standalone PyQGIS application?

I am trying to develop a standalone PyQGIS application. The map display does not pose any problems, but I do not know how to add a legend to the canvas.