Python bindings for QGIS.

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Help with scripts for processing raster files with the raster calculator in QGIS

I am trying to process some raster files using python scripts in Qgis 2.20, and I have been having trouble finding any documentation on using raster calculator in scripts being run in the processing ...
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1answer
224 views

How to add the attributes of selected features to my new layer in pyqgis

I am trying to create a layer from the selected points coordinates. I am drawing a circle to the coordinate of selected points. I also need to add initial attributes of my selected features to my new ...
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71 views

Multiparts and Multigeometries: checking for multigeometries with PyQGIS?

I have been working with PyQGIS and writing a small script to check whether the layers I have in the MapCanvas have geometries of type "MultiXX" because I want to run the "Multipart to Singleparts" ...
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1answer
141 views

QGis: scripting the map rendering (multiple similar maps from one shapefile)

I would like to ask for advice on creating a Python script that will provide the opportunity to render a plenty of similar maps (with the same extent, projection, layout, color scheme and composition, ...
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47 views

insertVertex giving false in pyQGIS

I have this code from my plugin which work in Qgis 1.8 and I am trying to make it work in 2.0. I want to insert a coordinate x and y into a polyline after the last entry. points = geom.asPolyline() ...
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14 views

Is there an equivalent of QgsMapToolIdentify in QGIS 1.8?

I'm using quantum gis 1.8 Lisbon, and I need to select a point that is on the map by mouse, to know their attributes. But I can not use the QgsMapToolIdentify function, that would show me another ...
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1answer
18 views

QgsMapToolIdentify(self.canvas)

I am creating a plugin in qgis 1.8.0 and need to get a variable that is saved in the point table. I was thinking about using QgsMapToolIdentify (self.canvas) function, but it gives me error ...
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17 views

Query from plugin that shows result on Map and in Attribute Table

I'd like to create a plugin that performs a static (no user input required) query that, based on a condition, selects all the features on the map and displays these in the attribute table. I have the ...
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1answer
239 views

Replacement of QVariant and setAttributeMap in PyQGIS

I am updating a plugin for QGIS 1.8 to QGIS 2.x. I have the code below. The setAttributeMap does not exist anymore. I have replaced it with fet.setAttributes and it seems to work. When using ...
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1answer
99 views

How can I reproject a layer in pyqgis?

I have a problem. I'm currently trying to get the extent of a vector layer in latitude and longitude coordinates in python. The layer is currently in EPSG:3857, so .fullExtent() is not returning what ...
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1answer
80 views

Alias's in the Attribute Table's Column Preview/Column Filters

We've spent some time setting up alias's in Layers/Properties.../Fields (Fig. 1) for database fields displayed as the column headers in the Attribute Table (Fig. 2). Switching the layout in the ...
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161 views

Issue blocking QGIS feature form dialog with Python

I'm not sure where I'm going wrong with this python logic for a custom form in QGIS 2.0.1. There are a few things required by the validation function: that index of combo boxes aren't 0 (first index ...
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120 views

How to eliminate gaps and overlaps in a layer of SpatiaLite table?

I'm try to snap all polygons in a table to remove gaps and overlaps. I can remove gaps but get new overlaps. I have no idea what doing wrong... sorry, I'm new in SpatiaLite. I tried the following: ...
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1answer
302 views

How to adjust QGIS attribute table view column width using Python?

I'm programmatically opening the Attribute table via Python through a plugin. All of the columns have a default width, but some of the data that I'm using do not fit. It's not enough to be able to ...
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0answers
91 views

Problem with QgsVectorFileWriter

I am trying to write a python script that when it is called it will take an .sqlite layer and save it as a GeoJSON layer. This will be used in a leaflet app but for now my problem is with this script. ...
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1answer
61 views

Displaying QGIS layer after loading with Python

I'm successfully loading several layers with Python, but can only get to see them in the map window if I manually zoom to extent afterwards. Once the last layer is loaded I call zoom to extent in the ...
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1answer
114 views

Python.dll could not be loaded with PyScripter

I'm trying to configure PyScripter with QGIS. I've installed it using OSGeo4W and I'm following instructions to setup a pyscripter.bat file by copying content of qgis.bat file. I have the following ...
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88 views

How to open QGIS attribute table in form view using Python?

I've got a plugin where I load some layers. On the last layer loaded I show the attribute table. I would like to select the view different from the table view (see image). How can I do this in Python? ...
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1answer
49 views

Retrieve path of running plugin in QGIS

In my plugin's directory I've got some XML settings files that I'd like to parse at a particular point during execution of the plugin. Is there a way to get the absolute path where the plugin's .pyc ...
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1answer
497 views

Can't select layer in the Road Graph plugin QGIS

I'm trying to use the Road Graph plugin in QGIS 2.2.0. I have tried a few line shape files, but it won't let me select the layer (the option is greyed out). I've tried adding a 'SPEED' field and a ...
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1answer
213 views

QGIS Map tools and Map canvas--QString errors

I'm trying to learn more about using QGIS Map Canvas widgets and creating custom map tools, so the information from the PyQGIS cookbook is very helpful. After trying to experiment with mywnd.py from ...
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1answer
174 views

How to clip a raster by a shapefile in pyqgis?

Currently I am working with some satellite images (grib files) in pyqgis. As I want to work only with the cells in my study area, I need to clip the raster by a shapefile. I know I can do this by ...
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2answers
442 views

How to set Eclipse and PyDev for QGIS when ArcGIS is installed?

I have got a lot problems with the configuration of Eclipse with PyDev in order to develop QGIS plugins. The situation is very weird and frustrating. I can import qgis module using Pyscripter without ...
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2answers
97 views

How to remove/disable a toolbar via python?

How do I remove or disable a toolbar e.g., Raster, programmatically using Python?
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27 views

Add a raster specifying the projection in pyqgis

I would like add an raster but I want to specify the projection. If I do : qgis.utils.iface.addRasterLayer(url,layerName) QGIS ask me to specify the projection. I want to this with python. How I ...
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37 views

Using pyqgis with existing ArcGIS files

I'm pretty new to GIS. I have some files that seem to have been created using ArcGIS (I got them from here http://www.fao.org/ag/againfo/resources/en/glw/GLW_dens.html). I would like to do some ...
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43 views

QGIS plugin, extending plugin stub, instance has no attribute error

Update This is not an answer to why it does not work when the method is defined inside the class, but a workaround. Simply defining the method outside, prior to, the class (something that Evil ...
2
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1answer
207 views

Got Null values when updating attributes with PyQgis

I'm trying to create and update a field and ,for now, just change it's value to 2. Here is my code: layer = qgis.utils.iface.activeLayer() index = layer.fieldNameIndex("P") # if index == -1: # ...
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1answer
585 views

How to merge shape files with attributes from a python script in QGIS?

I have some shape files. They are all the same kind of shape and all have the same attributes. If I wanted to merge them manually the "Vector/Data management tools/merge shape files to one" works ...
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1answer
780 views

AttributeError: 'module' object has no attribute 'Open'

Hy, I am running the following code which I found on: GDAL - Perform Simple Least Cost Path Analysis which I adapted to my case, but I get the following error when running the code in the python ...
2
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1answer
280 views

Failed load delimited layer in QGIS python console

I'm trying to follow the map rendering section from the pyqgis cookbook. I am able render shape file using qgs vector layer, however getting error prompt while loading delimited text file through qgs ...
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87 views

using postgis function in pyqgis

I'd use Postgis function in Pyqgis script. This code: qsql="(select gid, id, St_Buffer(the_geom,200) as geom from archi)" uri = QgsDataSourceURI() uri.setConnection("ip", "port", "x", "x", "x") ...
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350 views

Code works on python console in QGIS but same doesn't work in stand alone script

I'm trying map rendering with stand alone script, so I have small script which works fine in python console provided QGIS, however when I run same code in stand-alone script it executes without error, ...
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1answer
47 views

Rendering PyQGIS objects in MapCanvas

I'm quite new to PyQGIS and have what is probably a pretty basic question, but I haven't been able to pick it up from the documentation. I have a QgsVectorLayer object from a PostGIS server, and I ...
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36 views

Display errors with QGIS Python Console

I'm using qgis 2.0.1 and I'm just starting to try to use the python console. From what I can tell the functionality of the console is fine (I'm not getting any unexpected errors) but when I'm typing ...
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2answers
380 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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1answer
120 views

How to call a method by BOTH a button AND a key shortcut

I have been trying to call a method by BOTH a key shortcut (as described here http://www.qgis.org/en/docs/pyqgis_developer_cookbook/snippets.html) and a button I created on the toolbar. The button ...
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34 views

What's the conversion coefficient between millimeters and QSize units in Qgis?

What is the conversion coefficient between millimeters and QSize units in Qgis ? What i have in mind is to set the paper size (via setPaperSize()), knowing the size of the composed image. That is why ...
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1answer
42 views

how to compile qgis-1.8.0 on ubuntu

i have downloaded qgis-1.8.0.tar.bz2 and I want to install it on my linux computer(12.04 LTS). How can I perform it please? I do it because I am desperate with Qgis 2.0.1 Dufour on ubuntu 12.04, ...
0
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1answer
75 views

How to change the default gray color of the QgsComposition background?

I'm building a map, with elements like QgsComposerMap of course, but also QgsComposerLabel, QgsComposerLegend ,etc... Each of these elements has a boolean "setBackgroundEnabled" property, to make them ...
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4answers
166 views

Why QgsMapCanvas only appear after lost focus?

I created the simple frame .UI file, compiled with pyuic4, and tried the ShapeViewer.py to load the shapefile "world_borders.shp". However, the map doesn't display at the first time. I have to click ...
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28 views

random point through raster

I've some issue in some task pls help if you can as I've not good python skills. I've a raster with values from 5 to 97 and I want a python script which can scan the raster and generate random points ...
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91 views

Add memory layer to a preexisting PostGIS table

I'm trying to append a memory layer to a preexisting PostGIS table. The DB connection is already established (in this way: How to properly establish a PostgreSQL connection using QgsCredentials) and, ...
2
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0answers
119 views

How to fetch openlayers layers from pyqgis? [duplicate]

My objective is to fetch maps provided by openLayers, as in openLayers_plugin, from a stand alone python script. I would like to get it superposed to my shp file. As can be read on ...
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48 views

How to get the signal when the color changes in pyQGIS?

I would like to have the signal when the color of a vector layer is changed by the user. In the doc, there is a signal that seems to fit ...
2
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1answer
221 views

How to write a new layer to PostgreSQL from QGIS plugin

The PyQGIS cookbook states that QgsVectorFileWriter can write vector layers to any format supported by OGR: https://www.qgis.org/en/docs/pyqgis_developer_cookbook/vector.html#writing-vector-layers ...
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44 views

How to add field to postgres layer with PyQgis?

I'm fetching a posgtres layer with PyQgis and then I'm trying to add field with this: lyr.startEditing() lyr.addAttribute(QgsField("class", QVariant.Int)) But It is not adding the field and also ...
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44 views

Add feature to csv via PyQGIS

I'm using PyQgis 2.0.1. Is it possible to add feature to csv file? I've tried to do this as it's shown in CoockBook: if caps & QgsVectorDataProvider.AddFeatures: feat = QgsFeature() ...
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2answers
91 views

How to programmatically fill a datetime field with datetime.datetime.now() function

I have been trying to programmatically fill a datetime field using values coming from datetime.datetime.now() function. #I create the temp shp using a URI URI = ...
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0answers
90 views

How to apply categorized symbols to polygon layer with PyQgis?

I'm fetching a polygon layer from postgres like this: uri = QgsDataSourceURI() uri.setConnection("localhost", "5432", "mydb", "postgres", "xxx") uri.setDataSource("public", "my_table", "geom") lyr = ...