Questions tagged [pyqgis]
Python bindings for QGIS.
1
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0answers
22 views
How to read PyQGIS documentation? [on hold]
As I get more into QGIS scripting, I refer to the documentation often and usually without success. I have trouble deciphering how to interpret the classes, etc.
I've been really struggling to create ...
1
vote
1answer
28 views
How to remove legend items with PyQGIS without removing the layer?
I am trying to generate maps in pdf files by using a pre-defined .qgz layout. I am already able to load layers and adjust color scale, etc. Since the legend is synchronized with the map layers, all ...
-1
votes
0answers
20 views
add layers shown in Table of content as a input parameter [on hold]
I want to add layers shown in Table of content as a input parameter to a script which I written in python language.Can anyone help me to do this?
1
vote
1answer
27 views
Retrieve layer file path in PyQgis
I've been trying to list al file paths in my project using PyQgis (I'm not really acquainted with it); my goal is to translate and clip them all to export them to a folder
I've tried with:
names = ...
0
votes
0answers
26 views
Python QGIS .svg symbol with modifiable color (data defined override)
I can import an .svg format symbol on a vector layer by using QGIS Desktop App and change its color by using data defined override part(case when .. then rgb_color(255,0,0) END ). How can I implement ...
2
votes
1answer
62 views
Writing PyQGIS code to select items in line layer by length?
I have been trying to write a short code to select items in a line layer that are longer than 2000m, but I don't have much luck at the moment now.
layer=iface.activeLayer()
selected_fid=[]
lenth=[]
...
1
vote
0answers
26 views
Is there a way to use the project layout if using a plug in that creates batch maps through QGIS?
There is a plugin for biological records which creates batch maps for each taxon but it bypasses the premade project layout with a legend, picture of a logo and the copyright for each of them. Is ...
1
vote
1answer
20 views
Toggle labels on/off for a layer with PyQGIS 2?
I try to toggle labels on/off for a layer in QGIS 2.18 with PyQGIS. In PyQGIS 3 a method QgsVectorLayer().setLabelsEnabled() seem to have been added, but as far as I see, such is not available in ...
2
votes
2answers
35 views
PyQGIS QgsSvgMarkerSymbolLayerV2 setDataDefinedProperty() for color doesnt work
i have a script which works well and changes the symbol QuarterCircle's color and angle :
vLayer = QgsVectorLayer(uri, "myData" , "delimitedtext")
symbol = QgsSymbolV2.defaultSymbol(vLayer....
2
votes
0answers
34 views
Running python code created in QGIS
I'm using QGIS 3.4 and Python 3.7.0 on Windows 7.
From the Python console of QGIS, I created a test script ("test.py") which contains the following line:
print('Hello)
and this is saved in C:\...
2
votes
1answer
44 views
Running into endless loop when adding feature to layer with pyqgis
I am working on a script where I want the user to add feature to a layer in edit mode, and then decide whether to keep the newly added feature in the layer or not. I am doing it the following way:
...
1
vote
1answer
36 views
Hosting a few shapefiles so multiple users could use and edit the same map
Is there a way to synchronize a QGIS map with vector layers so that 3 or 4 users can use and edit the same file? I have a plug-in that updates shapefiles on a layer and it would be great to ...
1
vote
0answers
19 views
PyQGIS (3.4) and PyQt5 DLL error
I have installed the new version os QGIS(3.4) on my computer. I am working in a standalone application of PyQGIS so I need to load PyQt5 components. As a difference with previous versions when I try ...
1
vote
1answer
22 views
QDockWidget not showing content at first sight
I'm loading the QDockWidget and it does load fine and has the content but it seems that doesn't have a fixed size that avoids it's content to be hidden once loaded.
this is how it looks when is ...
1
vote
1answer
27 views
Add new feature to QGIS layer with pre-defined attributes using pyqgis
I am working on a pyqgis script where I allow the user to add features using the addfeature map tool, where the user can create the geometry of the feature by clicking on the canvas, and after the ...
1
vote
1answer
17 views
enable Advanced Digitizing Panel (cadDockwidget) with PyQgis
I am working on a PyQgis Plugin where I want to enable cad in advanced digitizing panel. Following pre-conditions are met:
layer is in edit mode
project has projected crs
move feature tool is ...
1
vote
1answer
25 views
PyQGIS (3.2) and H5PY DLL problem
I am working in a project in which I need to use PyQGIS and H5PY. The problem comes when I load qgis library and h5py, for example:
import qgis
import h5py
I get this error:
from ._conv import ...
1
vote
2answers
28 views
Python QGIS QgsSimpleMarkerSymbolLayerBase 1/8 Circle
How can I change the shape of simple marker to
simple_marker = QgsSimpleMarkerSymbolLayerV2()
simple_marker.setShape(QgsSimpleMarkerSymbolLayerBase.QuarterCircle )
not QuarterCircle(1/4) but 1/8 , ...
5
votes
2answers
199 views
Finding distance between point and polygon edge in eastward direction using PyQGIS?
I need to find distance in eastward direction from each point to the closest polygon edge:
I can find shortest distance in any direction with:
pointlayer = QgsProject.instance().mapLayersByName('...
3
votes
1answer
38 views
pyqgis - post-processing of layer output of QgsProcessingAlgorithm
While extending a plugin with a Processing Provider and a set of algorithms I mostly followed the defaults of Plugin Builder 3. So, the basic code is smth along the lines of
class ORSisochronesAlgo(...
1
vote
1answer
76 views
UBUNTU 16.04, QGIS 3.4 above Installation problem
I want to install QGIS 3.4 above and did exactly the same as this page:
QGIS Installers
and tried the codes below having no error at all:
(1) add the following lines to /etc/apt/sources.list
deb ...
3
votes
1answer
64 views
How to export a layout in standalone script with QGIS 3? [closed]
I'm trying to automate map export from a QGIS project in a standalone python script, without interface.
Many of the scripts founds are for QGIS 2.
For example the script written by Tim Sutton here.
...
2
votes
1answer
40 views
QGIS3.4 Madeira crashes when calling print()
I am using the pyqgis template from underdark for showing the crash. Her script is running like a charm, but as soon as I add a print("finished...")-call in her code, QGIS3.4 Madeira crashes.
You can ...
2
votes
1answer
66 views
Getting line geometry out of two points using QGIS?
I have one input point layer and out of that, I want to create an output LINE vector layer.
For each feature in my output line vector layer, I define a geometry which takes 2 point geometries. ...
2
votes
1answer
31 views
Loading QGIS Python tools in ArcMap? [closed]
How to load QGIS Python tools in ArcMap?
For example, if I want to use any GDAL or GRASS tools in ArcMap.
3
votes
1answer
28 views
Get number of changed features in a layer under edit mode using pyqgis
Is there a method I can find out, how many features in a layer have changed during edit mode (including changes in the attribute and the geometry)?
1
vote
0answers
42 views
QGIS 3 Python plugin psycopg2 Postgres Notify/Listen Live Connection
I'm developing a plugin for QGIS3 for my company, where my managers can allocate tasks to other users. I have programmed two tables within the python script, witch will be only visible according to ...
2
votes
1answer
28 views
Pyqgis Gdal_translate
I would like to transform tifs in a directory with using python in qgis 3 in order to make tifs with a diffrent crs and adding tfw file.
import glob, os
from PyQt5.QtCore import QFileInfo
from qgis....
0
votes
0answers
14 views
PyQGIS edit sample color by using expression (data-defined-override)
i have a .tab file which has a polygon geometry type.I want to change its colors according to some expression.In order to do this i could go properties>styles>simple fill>Edit(data defined override)>...
1
vote
0answers
16 views
PyQGIS 3D Map API
I can't find the way to show / hide / manage 3D map canvas in pyqgis. I've searched in API but nothing.
Is there a way to control the 3d map visualization from plugin like QgsMapCanvas?
0
votes
0answers
35 views
Allow access to PostgreSQL database only through QGIS plugin
I created a Python plugin in QGIS that manage the connection to my PostgreSQL database and loading layers in a specific structure, I've created also some personalized widgets to edit attribute tables ...
-5
votes
0answers
38 views
Which python library is best to use all GIS tools in python only? [closed]
Which python library is best to use all GIS tools in python only?
0
votes
0answers
21 views
GeoRefrencing in Gdal using x,y of four Corners
I have co-ordinates of all four corners of a raster and i want to Georefrence the raster using those co-ordinates,
I can specify the following in SetGeoTransform
# (uperleftx, scalex, skewx, ...
1
vote
0answers
29 views
Promoting to multipart using PyQGIS?
I am creating a code that aggregates neighbouring polygons if they have similar value on the field 'DN' and if they are closer than 50 m.Then I want to iterate this 3 times.
I could already get the ...
1
vote
0answers
31 views
Debugging processing algorithms in PyQGIS?
This is my code which should call processing alg selectbylocation and do intersection and touch between two layers. Next layer - points should intersect with the result of the previous layer. I typed ...
2
votes
1answer
48 views
Distance betweeen classified Points
I got two sets of points.
The first set has a unique ID
The second set references to this ID (one-to-many).
So I merged the two sets. Now every point in the joined table has the X and Y coordinates ...
1
vote
1answer
43 views
Categorized symbols are not working in QGIS 3.4
I'm trying to generate categorized symbols for a polygon layer in QGIS 3.4. The code below should generate random colour polygons for each record of 'run' layer and I'm not getting any error message. ...
1
vote
1answer
30 views
PyQgis won't find dockwidget child
Manually in the PythonConsole I can open or close panels but when is executed in code it won't find the dockwidget, this is the line I'm using in my code:
self.iface.mainWindow().findChild(...
1
vote
0answers
27 views
Failed to load python Qgis 3.4 add-ins
I installed Qgis 3.4 Madeira and it worked fine, but now it throws me two errors
The first is the following:
The second is:
By omitting the two errors that load with several defects, such as: a ...
0
votes
1answer
34 views
how to get first and last point of MultiLineString-objects in qgis3
i would like to identify the start- and endpoints within a set of polylines and return the coordinates of both points finally.
so far i have been able to iterate the features and found out that ...
1
vote
0answers
28 views
Is it possible to pass multiple WMS layer to a processing script
Is it possible to pass multiple WMS layers as parameters to a QGIS 3 processing script, similar to QgsProcessingParameterMultipleLayers but using WMS or WFS Layer? QgsProcessingParameterMultipleLayers ...
0
votes
0answers
11 views
pyqgis processing: running multiple tools in a single algorithm
I have the following code that executes the v.clean processing plugin:
params = {
'input' : input,
'type' : 1,
'tool' : 1,
'threshold' : 0.000095,
'output': ...
0
votes
1answer
31 views
Dissolving using PyQGIS?
I have trouble to use function dissolve to dissolve polygons by field value in PyQGIS3.
In PyQGIS2 this line was doing the job:
QgsGeometryAnalyzer().dissolve(ki, "name.shp", onlySelectedFeatures=...
1
vote
1answer
41 views
Compute 3D seismic fold with QGIS and Python
Computing 3D seismic fold is quite straight forward, for those unfamiliar with the concept, below is a brief explanation.
Background information (Seismic 101) :
Seismic Fold:
Basically, I have (...
0
votes
1answer
41 views
from qgis.gui import QgsMapCanvas - ModuleNotFoundError: No module named 'qgis'
I created a form with QT Designer, then converted it to a .py file. An error occurs with the line import : from qgis.gui import QgsMapCanvas. It's not recognized. How can I resolved this error in ...
1
vote
1answer
30 views
Run processing only in layers with selection
First of all, I am really begginer with PyQGis...
I am trying to run a random point algorithm in different vector layers of a folder. But I dont want to do it for every polygon, only for selected ...
0
votes
0answers
28 views
Pyqgis standalone - Matplotlib on QgsMapCanvas
Standalone mapping application:
Is possible to plot a point like scatter of matplotlib on QgsMapCanvas object?
I want to display my GPS current position without create a shapefile and edits it.
...
2
votes
1answer
64 views
How to open GPKG layer fo processing in QGIS
I am making a model with QGIS 3.4 graphical modeler that should open and process a layer from the GPKG located in the project folder.
Since the folder path may be changed, and QGIS does not allow ...
2
votes
1answer
106 views
Defining fields and adding features to output layer using QGIS?
I have two input vector layers (one point and one line layer). I loop through every feature in the input-line-layer and calculate some things (with help of the point layer).
What I am trying to do ...
1
vote
1answer
52 views
Making automatic updated date and time field in QGIS
I wish to create a field which automatically updates with the current timestamp when edits are made to a feature.
I am using QGIS 3.4 and I am testing this using a shapefile.
Following @Joseph's ...
