Questions tagged [pyqgis]
Python bindings for QGIS.
7,346
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How to get current (selected) tool from toolbars (map navigration tools & object selection panel) and change it in code [duplicate]
I'm developing a plugin for QGIS, and for further implementation there should be logic that automatically switches current tool to 'select objects', and, after selection, returns to the previous tool.
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21
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Reverse linestrings, given attributes
I am working with street numbering and toponymy and I have an issue in hands:
Given some data provided by an Institution, i.e.:
points as door numbering and
lines as the streets
Those streets were ...
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0
votes
1
answer
38
views
Correct way to specify Inputs and Outputs for QGIS processing scripts that use custom widgets?
Processing scripts do not allow parameter inputs to be changed by other parameter inputs. This can be overcome by defining a custom widget which does have the desired interactions, then using a '...
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1
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1
answer
21
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Generate layer preview icons
QGIS uses small image preview icons for its layers in the legend and layer tree. How can I create these for a given layer as an image object (QIcon or QImage I presume)?
As I am looking for a PyQGIS ...
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19
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MB Tile Error in QGIS [closed]
While generating MB Tiles following error is encountered:
Traceback (most recent call last):
File "C:\PROGRA~1/QGIS33~1.1/apps/qgis/./python/plugins\processing\algs\qgis\TilesXYZ.py", line ...
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33
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How to make old Python code compatible with QGIS v3.16 [closed]
We had some Python code in a QGIS v2.18 "Action" which emailed a recipient when we clicked on the action.
Now we are on QGIS v3.16 the code in the "Action" no longer works. Gives ...
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39
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AttributeError: NoneType
I have this code I use in the QGIS Python console. I used it a few days ago and it worked, but I tried using it again and I got this error:
Traceback (most recent call last):
File "C:\PROGRA~1\...
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33
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PyQGIS Push selected feature to identification results panel
I have selected feature on vector tile layer loaded from https://cdn.kadastr.live/tiles/maps/kadastr/land_polygons/{z}/{x}/{y}.pbf
How do I make its attributes appear in the identification results ...
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1
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36
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Selecting point/feature in layer using coordinates [closed]
I want to select a feature using my own coordinates.
Is that possible in PyQGIS?
I mean i enter my own coordinates and the program should select the feature at that specific coordinate if there's an ...
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1
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57
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Python script run error QGIS
I have been using the Python console in QGIS to develop a script. However, I keep getting the below error whenever I try to execute it.
This is line 43 which has the error
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59
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Fatal Exception (access violation) when executing QgsExpressionContextUtils.projectScope(QgsProject.instance()) inside a QgsFunction
QGis is randomly crashing and throwing "access violation" exceptions when I run the following line of code inside a qgsFunction:
QgsExpressionContextUtils.projectScope(QgsProject.instance())
...
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2
answers
83
views
PyQGIS VectorTileLayer feature selection by coordinates
I have vector tile layer in QGIS, loaded from https://cdn.kadastr.live/tiles/maps/kadastr/land_polygons/{z}/{x}/{y}.pbf.
How to select single feature of this layer by coordinates, in PyQGIS?
I am ...
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1
vote
1
answer
56
views
Create virtual/temporary layer from a GeoDataFrame in QGIS
I'm trying to make a plugin that lets me combine the Tracks from multiple GPX files into one virtual/temporary layer in QGIS.
Currently I have code that saves them as a GeoJSON layer but with a large ...
- 1,898
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7
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Install QGIS with the GRASS plugin enabled in a conda environment?
I am having issues using the GRASS plugin in QGIS in a PyQGIS script. I used miniconda on Ubuntu 20.04.6 LTS to create an env with QGIS using conda commands:
conda create -n qgis_test
conda activate ...
- 101
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1
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41
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QGIS - QgsProcessingParameterFeatureSource - Filter input layer
In QGIS, I try to write a script for a custom toolbox. I'm using the processing framework logic and following official documentation. I add an input vector layer, but I can't handle it has a ...
- 1,566
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41
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Building a WMS QgsRasterLayer from a QgsDataSourceUri
I have the following information for a WMS:
Base-URL: http://example.com/wms
CRS: EPSG:1234
Format: image/png
Layers: wms-layer
How can I use QgsDataSourceUri to create a WMS QgsRasterLayer from ...
- 10.2k
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2
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72
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Loop an operation in all features
I have a layer that has date and time information and I need the difference between this information in seconds, I managed to get close to this but I needed to loop for the difference between the ...
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1
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34
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Create the lines at a certain angle in PyQGIS
I want to create the lines at a certain angle? How can I do it?
Also The lines are coming out about 5-10 cm shorter than they should be. How can I correct this?
My code:
from qgis.core import ...
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-1
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21
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How to represent a shape 3-dimensionally in QGIS [duplicate]
I am working on verifying terrain clearance for a runway in QGIS. I have specific elevations for each vertex on the shape. How can I make this a 3 dimensional plane?
This is roughly the side view I ...
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1
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1
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78
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QgsMapToolEmitPoint(): argument 1 has unexpected type 'sip.wrappertype'
I have tried this code and several other similar versions and I always get this error
See Writing Custom Map Tools using RectangleMapTool
QgsMapToolEmitPoint.__init__(self, self.canvas)
TypeError: ...
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1
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2
answers
41
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QGIS: moving layers inside Layertree into a group crashes QGIS using python
I am trying to reorder the result of a model using python in the layer tree. For this purpose I wrote a script that takes the name and group as well as the the desired layer position in this group as ...
- 2,608
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23
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Using outside Python framework (ObsPy) in QGIS API (PyQGIS) [duplicate]
I would like to use ObsPy, a seismology framework for Python available at https://github.com/obspy within the QGIS Python API.
I have been able to use ObsPy to plot moment tensor solutions in an ...
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48
views
Adding slope to lines drawn using PyQGIS
I want to add a slope to lines drawn using PyQGIS. The lines drawn with PyQGIS are currently green, but I want them to appear brown. How can I achieve this?
The code I wrote:
import math
from qgis....
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15
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Custom Feature Form - Add multiple Features - Crashes when commiting
I use a custom feature form to set new features for my point layer.
Beause i have to set many points i dont want to open the form new every time i set a new point.
Thats why i added a function which ...
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15
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QGIS Flatpak installation 'ModuleNotFoundError' under Linux Mint
I'm pretty new to Linux and trying to install QGIS with some extra plugins for hydrodynamic modelling.
I followed the instructions regarding the flatpak installation on qgis.org. After installing the ...
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1
answer
39
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How to export a jpeg image with a raster layer extent in PYQGIS?
I'm struggling with this issue from weeks. I wrote this code in order to:
load a raster layer (image of a port)
Taking only the gray band of it
load a mask to put on top of it and set it black
export ...
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0
answers
32
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How to use the field calculator array_mean() function in Python console QGIS
I have a layer with USA counties; each county has a unique identified 'COUNTYNS' and a field "CO_mean_microg_m3". Some counties have this CO value as NULL, so I want to take the 6 nearest ...
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1
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30
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Loading S3 hosted COPC (LAZ) in QGIS 3.28.9 using Python
I am attempting to loop over dozen of https S3-hosted COPC (LAZ) files in Python for QGIS to (1) render them, and (2) write out a simple thumbnail Jpeg. Using the script below I can successfully loop ...
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31
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Batch processing layouts with several shapefiles based on master layout
I'm trying to batch some layouts based on a master layout through the python console in QGIS. Basically, what I'm trying is to generate a layout like the one below and print a *.png of the layout.
I ...
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31
views
Accumulated distance between points
I have this piece of code that I can make lines between points and calculate the length of the line, but now I need to calculate the accumulated distance only between the X axis, I managed to use ...
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2
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2
answers
124
views
Calculating main_angle of polygons using PyQGIS
According to Calculating Polygon Main Angle using QGIS, it is possible to find the main_angle of a polygon by using a field expression like:
main_angle($geometry)
Can this function be called using ...
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30
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QPushButton : disconnecting the clicked signal
I am using QPushButton called 'add_routes_pb'
I am connecting its 'clicked' signal to a slot function i.e 'Add_routes_func' which is in another class.
Problem Faced: The problem which I am facing is , ...
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1
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32
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Handling intermediate service layer errors in Python
I have a QGIS project with a WMS (QgsRasterLayer) and a WFS (QgsVectorLayer) layer.
These layers might encounter random issues, e.g. missing network access or parsing errors.
How can I be notified ...
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34
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How to export vector layer containing symbology compatible with ArcGIS on PyQGIS
I export vector layer(.shp) with symbology file(.qml) like below code.
The exported files works on QGIS, but on ArcMap (ArcGIS), qml file doesn't work.
How can I extract symbology file on PyQGIS so ...
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1
answer
106
views
QGIS action Python recover id after paste
I have 3 layers:
a point layer (1) with id,
a polygon layers origin (3) with id_1.
a polygon layer destin (2) with id, id_1 et id_p.
I want to copy the polygons from layer 3 (which I select with the ...
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1
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1
answer
43
views
Select several layers by name using an expression
I'm am new to using PyQGIS and this question has been answered in various forms already, however not specifically the way I need it; I have a big QGIS project with several layers with similar, but not ...
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28
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shortestpathpointtolayer
I am trying to use the shortestpathpointtolayer function in QGIS with Python as below.
start_points = QgsProject.instance().mapLayersByName('start points layer')[0]
end_points = QgsProject.instance()....
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40
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Read Project File in QGIS Macro
One of the things I really like about ArcGIS Pro is that, when you start a new project, it prompts you to create a new .gdb associated with the project. I'm attempting to replicate this behavior in ...
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19
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QGIS version 3.32.1, after packaging independent application loading raster data could not correctly read the coordinate system
QGIS version 3.32.1, secondary development in PyCharm, after packaging independent application loading raster data could not correctly read the coordinate system。
autorsrs.py：
if __name__ == '__main__'...
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3
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1
answer
84
views
How to authenticate to download images from https://landsatlook.usgs.gov/stac-server
I am building a QGIS plugin in Python to fetch Landsat images from this STAC server:
https://landsatlook.usgs.gov/stac-server
I need to be able to download the thumbnails, but cannot find how to ...
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35
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QGIS processing script crashes while trying to set layer styles
So i recently tried to improve my script for automatically setting the style of vector layers from a folder filled with ".qml" files. It usually crashes around the 4th or 5th layer, and if i ...
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1
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23
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Update labeling expression and properties with PyQGIS
With PyQGIS API, I need to set labeling expression and text color dynamically before exporting the map to different file formats using QgsLayoutExporter.
The code I use:
layerTree = QgsProject....
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52
views
How to change output layer name when using processing algorithms in own PyQGIS script
If I execute the following example PyQGIS script, the temporary output layer is called "Remaining fields" in the layers panel which is the standard output layer name of the last executed ...
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26
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Import QWebEngineView into PyQGIS script
I'm working on a project that should interact with Google Maps API.
Usually I use QWebView as a widget to load web pages. But my simple html page is not loading there. However if I load the original ...
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17
views
Accessing model using PyQGIS
I've tried various ways to acccess my *.model3 file using PyQGIS libs as standalone script.
I can access and run my model from script stored inside QGIS.
processing.run('model:my_model_name', params)
...
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1
answer
21
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processing.run wont work with filter on layer
I have a pyqgis script in my plugin. There I like to execute a process:
new = processing.run("native:splitwithlines", {'INPUT':QgsProcessingFeatureSourceDefinition('table-path-to-the-db', ...
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27
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PyQGIS: Remove a legend item NOT the whole layer from the project
I have a number of vector layers and, occasionally, an image basemap.
I am creating a layout programatically based on this data.
I have a legend but I have zero want or need for the basemap raster ...
- 179
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1
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51
views
Hide the "Quick Field Calculation Bar" in QGIS
I want to hide the Quick Field Calculation Bar (see image). I found this old thread:
Disabling FieldCalcBar in QGIS
but sadly it does'nt work in QGIS 3.28.
Does anyone know what the quick field ...
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1
vote
1
answer
100
views
import pyarrow fails even when installed
I need to use the pyarrow package on QGIS 3 (using QGIS 3.32.2 'Lima') on Windows 11, and install it in OSGeo4W shell using pip:
pip install pyarrow,
which installs 13.0.0 by default as I'm writing ...
1
vote
2
answers
49
views
Call and Run PyQGIS script by plugin
I wrote a code that work well in console python, an example:
from qgis.core import QgsProject, QgsLayerTreeGroup, QgsLayerTreeLayer, QgsLayerTree
from PyQt5.QtCore import Qt, QVariant, QSettings, ...
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