1
vote
1answer
56 views

Why is feature.geometry() None in my user-defined expression function?

I'm trying the user-defined expression functions for QGIS, as listed on Nathans blog: http://nathanw.net/2012/11/10/user-defined-expression-functions-for-qgis/ I always get the feature.geometry() as ...
2
votes
1answer
18 views

QGIS Processing - Additional Creation Parameter for GdalWarp

I am having a hard time getting the "Additional Creation Parameters" to work when using GdalWarp through the processing toolbox. I am trying to set the nodata value to 0 for the output raster. ...
2
votes
1answer
36 views

PyQGIS - Start/Stop Editing with data Provider - Commiting changes

I want to edit a specific field for a QgsVectorLayer, within a QGIS application. I am facing inconsistent results from my code, ie: changes are not alway commited. Please could someone point me to ...
2
votes
0answers
15 views

Refreshing “layer render order” widget

i made changes in the render order of my map canvas using a : qgis.utils.iface.mapCanvas().setLayerSet(a) "a" being a list of QgsMapCanvasLayer My code is working as expected (i see result on map ...
1
vote
1answer
41 views

Programmatically export a Qgis project

I have a QGis project that I programmatically modify using the Python xml.etree library. Now, I would like to know if it is possible to add few lines to my script in order to export the modified ...
1
vote
0answers
29 views

Retrieve a point coordinates from map canvas using QGIS API

I'm trying to build a plugin that firstly captures the map coordinates. I have tried to adapt the map tool explained in this post: How to programatically check for a mouse click in QGIS The code I ...
2
votes
0answers
19 views

Memory layer or QgsVectorFileWriter Error?

Currently this excerpt of code will not save to file (as it is supposed to). The memory layer is visable and editable. Yet even when manually saving the layer, any priorly added features ...
2
votes
1answer
25 views

QgsMapCanvas.reresh() does not reload new wfs layer features, but panning does

I have a wfs layer loaded in a standalone QGIS app, which I am updating by running a database query on the view it is based on. The feature is added with no problems and I reload the layer with: # ...
3
votes
1answer
35 views

Changing attribute values in a memory layer

I'm trying to change attribute values in a memory layer. My memory layer is defined in this way: pro.addAttributes([QgsField("nom", QVariant.String), QgsField("valeur", QVariant.Int)]) I made ...
1
vote
1answer
18 views

How to set QGIS options in standalone pyqgis application

I have a standalone application which uses the QGS api to view and query map layers. One layer is a WMS-C layer which automatically caches tiles which is great. I want to also activate a setting which ...
2
votes
0answers
16 views

access point layer representation in qgis with pyqgis

I am exporting the style of a categorized point layer with qgis: unfortunately my code only extract the size of the symbol in the definition of the properties of the layer but not the ...
3
votes
1answer
33 views

Why is the SelectionChanged signal triggered every time i click on the layer?

i'm making some experiments with the SelectionChanged signal of a QgsVectorLayer. i try this piece of code : curLayer.selectionChanged.connect(self.test) and "test" print a warning message. The ...
0
votes
1answer
46 views

How to delete column/field in PyQGIS?

How to remove or delete column fields in a shape file using python?
2
votes
0answers
38 views

How to add a TIF raster layer programmatically?

This is my code whenever i try to load .tif image it shows layer is not valid,QgsRasterLayer always return invalid layer (I am using linux 12.04). QString myFileName = ...
0
votes
0answers
33 views

Is there a way to take control of the mouse pointer using python in QGIS?

i would like to take control of the mouse pointer in QGIS (for example constraining it to a given extent...) Is there any way to do that using PyQGIS ? Thanks !
1
vote
0answers
32 views

Modifying properties of Attributes Table in QGIS?

In my QGIS project I'm using vector layers that require a lot of data inputting/editing. The problem is that some of the data I'm inputting varies greatly in matter of length and structure (various ...
0
votes
0answers
19 views

How to move a layer in QGIS Toc above an existing group?

If in QGIS TOC a group already exists and I add a new layer via QgsVectorLayer* lyr= mQGisIface->addVectorLayer(uri->uri(),Title, myProviderName); the new layer will be inserted within the ...
2
votes
1answer
53 views

How to add labeling to a polygon layer?

I'm trying to add labeling to a polygons vector layer called "myVectorLayer". It does not give me an error but the labeling does not appear. palyr = QgsPalLayerSettings() ...
1
vote
0answers
36 views

PyQGIS: Editable Combobox for Value Map widget isses

I am having issues with an editable combo box in QGIS 2.4. The edit widget is set to Value Map with an uploaded CSV. However, if a new values (not included in the key value pair list) is added, the ...
2
votes
0answers
26 views

Add a new polygon to an existing shapefile from wkt in QGIS

I have a layer of polygons in QGIS; I want to add programatically (pyqgis) a new polygon to this layer using WKT. Example: mywkt = POLYGON ((522762 376413 0,530635 368671 0,522237 353713 0,522762 ...
0
votes
2answers
60 views

Error while importing CSV File using PyQGIS

Currently I am trying to import a CSV file using the python extension in QGIS and I have run into a problem that I can not seem to solve. I am trying to do a basic import of a CSV file from a python ...
1
vote
1answer
32 views

What causes this error when loading plugin

After installing pyspatialite on my Mac two plugins fail to load with this error:: This plugin is broken invalid literal for int() with base 10: '2-spatialite' I am fairly sure that the offending ...
0
votes
0answers
27 views

pyQGIS : Way in order to know modifications?

I 'm writing a pyqgis script. I succeed in accessing gis vector data (lists) from my remote server (thanks to urllib) . I succed in displaying geometries and attributs. 1/ Now, i would like manage ...
0
votes
2answers
151 views

QGIS 2.4: plugin changes map tool canvas click behavior from 2.0

I had created a plugin for QGIS 2.0 to add new features more easily. It involves changing extents and updating snapping options along with triggering the default actionAddFeature(). However, I've ...
0
votes
1answer
27 views

How to read Oracle data with PyQGIS? (“identifier is not long” error)

Do you have any idea how load Oracle spatial data to QGIS with using the PyQGIS? Is it possible? I try: uri = QgsDataSourceURI() uri.setConnection("*host*", "1521", "*database*", "*username*", ...
0
votes
0answers
17 views

v.clean in QGIS Python console

I have tried to use v.clean and v.clean.advanced (by GRASS GIS) within a script in QGIS, and was not able. I followed instructions here:, but was not able to do so. I got message: "No module named ...
0
votes
1answer
77 views

Print custom feature form using PyQGIS

I am looking for a way to print a custom feature form created in PyQt Designer for QGIS 2.4 using PyQGIS. My goal is to print/save image as the current extent of the map with the selected feature's ...
1
vote
1answer
43 views

How to interact with other layers in a QGis Python init function?

I am using QGis and making a Python script that sets the Python Init function to a custom UI file. I have a function with the following signature: def formOpen(dialog, layer, feature): ... I ...
0
votes
0answers
25 views

Error when providing “Python init function” from Python script in QGis

Problem I am using QGis and Python scripting to programmatically set a layer's edit form and "Python init function". It appears that the Python init function is called correctly in one situation ...
1
vote
1answer
45 views

QgsMapRenderer to export current extent using PyQGIS

I am trying to accomplish PyQGIS simple map rendering via the QGIS 2.0 Python console, but end up with only a blank image. I've followed instructions of this link. My objective is to export a simple ...
0
votes
0answers
43 views

gdal_translate from within pyqgis [duplicate]

I want to use gdal_translate from within a python script in my plugin qgis2leaf. I've tried with ...
1
vote
2answers
52 views

How to switch to edit mode vector layers, in pyqt application based on qgis?

I do QGIS based application, I need to implement the ability to modify the geometry of vector layers in manual mode (editing nodes), how to do it?
0
votes
0answers
27 views

QGIS - Calling interpolation extension from python console

I would like to call the QGIS interpolation extension function (TIN method) (Raster->Interpolate) from python console. I can't find the corresponding function within QGIS API or within the ...
0
votes
1answer
62 views

How to open, modify and save a QGIS project with PYQGIS

I need to create a stand-alone script for opening a QGIS template project, modify a layer data source, export the Composition and finally save the modified .qgs project into a new file. So far I have ...
1
vote
1answer
59 views

How to programmatically export a composition as image?

QGIS Print Composer has tool "Save As Image" and I found appropriate function in QGIS source code exportCompositionAsImage. Is it possible to get access to existing Print Composer from Python console ...
0
votes
0answers
38 views

Couldn't load PyQGIS in QGIS 2.2 on Ubuntu 14.04 [duplicate]

This issue appears to be occurring with some frequency to folks in some shape or form. I upgraded from ubuntu 12.04 to 14.04, with loss of python functionality. My QGIS version is 2.2 from the ...
0
votes
1answer
34 views

QGIS API documentation in French?

I am looking for a document which explains what the API of QGIS is, with examples of this API but in French.
0
votes
0answers
22 views

Is it possible to customize openFeatureForm of pyqgis?

I am a beginner in PyQgis. I am trying create a plugin, which will be used to AddFeatue,Delete Feature, and Edit the Feature. It is more customized than which is provided by Qgis (2.2). I am capturing ...
1
vote
2answers
63 views

How to get features based on their attributes using Python - special characters?

I want to get features based on their attributes and it works fine when I use this Python script: canvas = iface.mapCanvas() curLayer = canvas.currentLayer() it = ...
2
votes
1answer
84 views

How to find the id of the last added feature using pyQGIS?

Is it possible to programmatically (in python) access the attribute info of the last added feature in QGIS 2.0 before edits are saved? I'm failing to find a way to get the ID and subsequently other ...
1
vote
0answers
80 views

Using qgis modules in standalone application with PySide?

I want to make small standalone application using PySide and QGIS python modules to display satellite images and do standard GIS operations, like creating new shape file and placing polygons or points ...
1
vote
1answer
40 views

How to add an interpolation raster from the python console in QGIS?

I'm trying to add an interpolation layer based on an existing vector layer by using the Python Console (initially in the menu Raster/Interpolation), but can't find anything related in the ...
0
votes
2answers
112 views

How to make a routable graph from a Point and a Line shapefile, using Networkx?

I have one shapefile which consists of all the streets in the study area, and another shapefile which has points representing origins and destinations. I would like to know if it's possible to find ...
1
vote
1answer
117 views

How to make a Python script that does a task in QGIS?

When I run this code in QGIS Python console it works fine, but I want want to run it from an external Python script. What I want the script to do is: 1- Open QGIS 2- Run this code 3- Close QGIS from ...
0
votes
0answers
32 views

PyQGIS: Programmatically Adding Point Features via QgsMapToolEmitPoint

I've created a map tool for QGIS 2.0 Python plugin that emits a point with the click of the mouse. I'm trying to create an edit tool, adding a point feature at the emitted point while selecting ...
0
votes
1answer
40 views

How to integrate pascal code into a QGIS model or plugin?

I have a console program that is written in pascal (lazarus) that reads in some raster files and parameter values as input. The code use dynamic 2D arrays to represent the rasters. I would like to ...
0
votes
1answer
37 views

PyQGIS: How to send signal to call unsetMapTool()

I've created a map tool to add some functionality to adding point features in QGIS 2.0. I'd like to unset this map tool if editing has manually been terminated by user. I've attempted as shown below, ...
0
votes
0answers
43 views

PyQGIS: QgsMapTool to add point feature

I am having issues programmatically adding point features using QGIS 2.0. I am trying to add a point feature, select another layer's nearby feature, and open the feature form to enter attribute data ...
1
vote
1answer
72 views

Iterating over selected features in QGIS Processing

I used to be able to iterate over selected features using the following script in v2.0. import processing features = processing.getfeatures(layer) for feature in features: #Do whatever you need ...
0
votes
1answer
63 views

Programmatically set layer properties Python Init function

Is it possible to set the layer properties Python Init function field programmatically? I've been looking through the qgis 2.2 api but can't seem to find anything on it. Hint, suggestions and ...