Python bindings for QGIS.

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1answer
19 views

If statement using QgsRasterCalculator

So in the sequence of my previous question (Can't use Raster Calculator with two different rasters), I am stuck again in my project. With my source rasters, I created 3 different outputs using ...
2
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0answers
10 views

QGIS - Display features only if labels are displayed

In my maps there are several point layers, and each layer has a different labelling rule and priority. Sometime the point density is too high and the labelling engine is not displaying some labels, ...
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1answer
16 views

Why use QgsFeatureRequest() when iterating?

I am unclear on why one should use QgsFeatureRequest() when iterating over a file’s features. Let’s say I would like to print out all IDs in my currently active dataset. Now, most examples will ...
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1answer
63 views

How to select and zoom in features from a QGIS Python Plugin

I'm very new to Python. I'm trying to find a way to select and zoom to the features from a QGIS layer. I've created a plugin and built a custom form. I have 3 values from the form which I need to ...
2
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1answer
115 views

How to load a *.qgs file in a C++ QGIS standalone app?

I'm using QGIS-2.4.0 API to develop a standalone app by C++. I saved a test.qgs file in QGIS Desktop software, in the project, there was one layer and it was visible. Then I loaded the test.qgs ...
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1answer
66 views

Run processing toolbox outside QGIS in standalone app

I am developing a standalone app in Python, using QGIS libraries including processing algorithms. I am developing in Linux environment and I put the libraries in a folder. Also I put the processing ...
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2answers
548 views

How to write scripts that can call on both Arcpy and PyQGIS?

I have spent quite a bit of time looking for a clear answer this topic and have still been unable to really accomplish my goal of accessing PyQGIS in a stand alone script. Parts of answers have been ...
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1answer
24 views

User Interface file compilation using OSGeo4W shell during qgis plugin creation

I am trying to build a plugin in Qgis2.6 using plugin builder. And as a part of the same, I tried compiling the .ui and .qrc file using OSGeo4W shell. It is showing an error during compilation in ...
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1answer
21 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? ...
2
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0answers
23 views

How to select the features by freehand in qgis using python programming

I have one polygon layer with 10 features. when i draw a line by free hand on the polygon layer it has to select the features. But when i am using qgis.utils.iface.actionSelectFreehand().trigger() ...
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2answers
525 views

Load and display a layer using PYQGIS

I'm having a go at using pyqgis from within the QGIS python console to load a layer from SQL Server and display it. I feel like I'm part way there but I'm having a real issue getting the layer to ...
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2answers
266 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. ...
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1answer
37 views

How to create a text file containing layer names in QGIS?

My QGIS ToC contains layer groups and some layers that do not belong to any group. I would like to create a text file containing the name of those layers that do not belong to any group. Is there an ...
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1answer
25 views

QGIS 2.6 : Programmatically setting key value pairs for ValueMap widget

Using QGIS 2.6 and Python 2.7 on Windows 7, I am trying to programmatically insert key value pairs into a ValueMap widget via a csv file. Issue is that some of the values are properly inserted and ...
2
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0answers
33 views

How do the architecture in qgis plugin creation is linked with eachother using plugin builder?

I am just trying to understand how the architecture or the workflow is linked each other while QGIS Plugin creation using plugin builder. It would be better for me to understand if anyone explains ...
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2answers
677 views

How to debug 'Layer is not valid error' from Python plugin?

I'm trying to understand what goes wrong with a QGIS python plugin. Basically I'm trying to render a series of POINT. The query works fine, at least giving it by hand from inside PostGIS DB: "SELECT ...
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1answer
73 views

How to add fields to shapefile from standalone script?

When I run the following script via OSGEO4W64 Shell, I receive the following error when trying to run the qgis:fieldcalculator algorithm: 'NoneType' object has no attribute 'mapCanvas' I read ...
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0answers
26 views

QgsRubberBand with holes

I tried to create a QgsRubberBand object with holes, but failed: rb = QgsRubberBand(iface.mapCanvas(),True) geom = QgsGeometry.fromWkt("POLYGON((0 0,4 0,4 3,0 3,0 0),(1 1,3 1,3 2,1 2,1 1))") ...
6
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1answer
65 views

Why the order of imports matters in a standalone PyQGIS processing script?

I've come across a weird issue while running standalone PyQGIS processing scripts. The order of imports in the script affects its normal execution. You can reproduce the problem by opening a Python ...
3
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1answer
995 views

legend groups and layer position/order qgis 1.8

I'm tring to programmatically create layer sequence also using groups. Simple python code: layer = QgsVectorLayer("004cp000.shp", "004cp000", "ogr") QgsMapLayerRegistry.instance().addMapLayer(layer) ...
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2answers
1k views

Setting the extent for a QGIS map using python

I am writing a stand-alone application in Python/QGIS that simply creates maps. I want to load vector/raster layers, set symbology, set extent At the moment, that is all! Currently I am just using ...
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0answers
19 views

Error while creating QGIS plugin

I tried developing a python plugin in QGIS2.6 following the instructions in the link http://anitagraser.com/2014/04/26/getting-started-writing-qgis-2-x-plugins/.When I launch the plugin in QGIS after ...
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1answer
49 views

Load the raster image which is in TIF format using QGIS API

I am quite new inthe field of GIS. I am interested in is to load the raster image which is in TIF format using QGIS API I have followed the steps given the in the follwing link to load shape file ...
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1answer
22 views

How to select features using an expression with pyqgis?

How can I select features with pyqgis using an expression? I tried to use an QgsExpression but the select method doesn't take it: exp = QgsExpression("'ogc_fid' = 482") cLayer = ...
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1answer
27 views

How to zoom to selected feature with QGIS Python Console

I want to select a feature by ID and zoom to it. I tried the following but the canvas doesn't change. Any ideas? canvas = qgis.utils.iface.mapCanvas() cLayer = canvas.currentLayer() cLayer.select(51) ...
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2answers
35 views

Is there scripts of QGIS core plugins available anywhere?

Is there anywhere I can see the scripts of the Qgis core plugins.
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3answers
2k 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 ...
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2answers
25 views

How can I disable logs being created in standalone python script?

When I run the following script in QGIS 2.6.1, it produces a folder called 'processing', which contains a log, in the directory it reads files from. And since the script reads files from several ...
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0answers
46 views

How to modify current QGIS canvas from python script?

I want to zoom into the current active QGIS canvas from a standalone python script. I tried the following but it doesn't impact the current QGIS canvas: import qgis.utils canvas = ...
2
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1answer
161 views

How can I add grid lines to a print composition using pyqgis?

I'm writing a qgis plugin to create an image in the print composer of the current map. I can get the map rendered in the proper place with a frame of the right width, and I can get grid annotations ...
3
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1answer
36 views

How to add a column/feature with PyQGIS 2.x?

I'm using PyQgis 2.2 and I'm creating a plugin. I want to add one feature/column to a shapefile. But I get error.. I've tried to do this as it's shown in Cookbook: if caps & ...
2
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1answer
48 views

How to get shapefile extent from standalone script?

I am trying to obtain the extent of a polygon in a shapefile. I am running a standalone script which will create a grid based on the extent of the polygon. I have tried 2 methods: one from the ...
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2answers
175 views

Save a layer for each unique value using Python in QGIS

I have a map, in which each region is defined as an attribute of the map (I can select each region from the attribute table). I am trying to create new layers each one containing only 1 region using ...
3
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1answer
52 views

Removing a vector layer from QGIS [duplicate]

Considering my program is generating a shapefile that has to be added to the "Layers" tab in QGIS interface. However, once the utility of the layer is completed, I need to remove the layer in the ...
3
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1answer
49 views

Add button to custom standalone QGIS application

Im able to implement zoom in and zoom out functionality as described in the PyQGIS developer cookbook using a tool bar. I would like to have buttons that display above my map canvas layer and have the ...
3
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0answers
14 views

Error writing buffered memory layer to shapefile in QGIS

I have created a memory polygon layerin my QGIS plugin. Then I added a buffer based on a point. I can see the ploygon layer in the map canvas and I can save it to a shapefile from the main GUI. But ...
2
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2answers
146 views

pyqgis: AttributeError: 'QgsRasterLayer' object has no attribute 'drawingStyle'

qgis gurus. I have a question about pyqgis and hopefully I can get some advise here. I am following http://www.qgis.org/en/docs/pyqgis_developer_cookbook/intro.html. In python console after a raster ...
2
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2answers
88 views

IdentifyFeature() use via PyQGIS?

Intent is to have two variables (QgsVectorLayer and feature.id() within said layer) as input for the Identify feature map tool in Qgis (2.6). Wondering if a feature can be selected programmatically ...
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3answers
89 views

Saving a QGIS project using the API loses mapcanvas (and other) XML nodes

I'm using the following python script to open a QGIS project, modify some things, and save it under a different name: from PyQt4.QtCore import QFileInfo from qgis.core import * def main(): ...
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votes
3answers
1k views

How do I get the path of a project, or layer file in PyQGIS?

I am generating new raster files from vector layers on a project. I would like to save them in the same directory as the project or layer files. How do I find this path using PyQGIS?
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3answers
67 views

How to use PyQGIS spatial index efficiently?

The PyQGIS Cookbook explains how to set up the spatial index but it only explains half of its usage: create spatial index — the following code creates an empty index index = QgsSpatialIndex() ...
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2answers
2k views

How can I fix “ImportError: No module named qgis.core”?

First of all, I'm using Python 2.7.3, QGIS 1.8 (Lisboa) on Windows 7 pro 64 bits. Now let's go to the actual question: I have written some code (Python) that works well within the QGIS built in ...
2
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1answer
101 views

Accessing CRS info with pyqgis in a standalone application

I'm currently having trouble accessing and defining CRS information in a standalone application. I've read the API documentation and have tried it in the python console in QGIS 2.2.0. The python ...
3
votes
2answers
421 views

Access Sextante (processing) in standalone QGIS app?

Sextante is addressable via python using the QGIS python console (unfortunately not from outside QGIS). I´m writing a standalone app and want to include Sextante geoprocessing functionality. In QGIS ...
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5answers
1k views

How to run sextante algorithms outside of qgis python console?

I'm kind of stuck trying to figure out the way to run sextante from a standalone python from OSGeo4W distribution. The reason I want to do this is that I got tired entering parameters in the dialog ...
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2answers
380 views

How to use SEXTANTE in a script outside QGIS?

I´m trying to do some geoprocessing using the QGIS Sextante plugin outside of the QGIS application (and integrate it with different other libraries like arcpy, etc.). import sys, os from PyQt4.QtGui ...
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2answers
190 views

Cannot run standalone QGIS script

I've been trying, along with this post, to run a script in OSGeo4w Shell, outside of QGIS. But I get the following error: ImportError: No module named qgis.core I have also read the following ...
2
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2answers
123 views

How to use QGIS explode lines 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 * ...
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1answer
105 views

Use PyQGIS to import CSV and draw points using different color

A CSV file contains columns latitude, longitude and color. uri = "file:///C:/data/balls.csv?type=csv&xField=longitude&yField=latitude&spatialIndex=no&subsetIndex=no&watchFile=no" ...
2
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1answer
46 views

Calling canvas.saveAsImage from script in QGis -Qstring problem

I want to create a processing script that saves the QGIS MapCanvas exactly as it is seen on the screen and then Zip up the tifw and a created PRJ. The existing QgsMapCanvas.saveAsImage()-method does ...