Python bindings for QGIS.

learn more… | top users | synonyms

2
votes
1answer
157 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 ...
0
votes
0answers
67 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. ...
1
vote
1answer
49 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 ...
1
vote
1answer
87 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 ...
2
votes
0answers
63 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? ...
0
votes
1answer
41 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 ...
1
vote
1answer
330 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 ...
1
vote
1answer
118 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 ...
0
votes
1answer
76 views

How to clip a raster by a shapefile in pyqgis?

Currently I am working with some satellite images (grib files) in pygis. As I want to work only with the cells in my study area, i need to clip the raster by a shapefile. I know í can do this by ...
1
vote
2answers
274 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 ...
2
votes
2answers
80 views

How to remove/disable a toolbar via python?

How do I remove or disable a toolbar e.g., Raster, programmatically using Python?
0
votes
0answers
20 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 ...
1
vote
0answers
36 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 ...
0
votes
0answers
33 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
votes
1answer
102 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: # ...
4
votes
1answer
265 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 ...
0
votes
1answer
306 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 ...
1
vote
1answer
132 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 ...
0
votes
0answers
58 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") ...
0
votes
1answer
187 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, ...
0
votes
1answer
44 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 ...
0
votes
0answers
28 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 ...
3
votes
1answer
174 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 ...
1
vote
1answer
93 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 ...
0
votes
0answers
24 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 ...
0
votes
1answer
26 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
votes
1answer
59 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 ...
0
votes
4answers
109 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 ...
0
votes
0answers
19 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 ...
0
votes
0answers
70 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, ...
1
vote
0answers
75 views

How to fetch openlayers layers from pyqgis?

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 ...
0
votes
0answers
44 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
votes
1answer
118 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 ...
0
votes
0answers
42 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 ...
0
votes
0answers
40 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() ...
0
votes
2answers
61 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 = ...
1
vote
0answers
56 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 = ...
1
vote
0answers
66 views

Install PyQGIS in virtualenv

Is it possible to install PyQGIS in virtual environment? I want to use rendering capabilities in my own application which runs using virtualenv.
0
votes
0answers
104 views

PyQGIS + PostGis: FATAL: sorry, too many clients already

I searched for questions regarding this problem and hadn't find one. I'm developing a custom application with a map canvas to show some geographic information from a PostGis database. After some ...
2
votes
1answer
62 views

How to properly establish a PostgreSQL connection using QgsCredentials

I'm trying to establish a Postgres connection using QgsCredentials as described here: How to access user credentials in database connection? The only problem is that I cannot establish a working ...
4
votes
1answer
126 views

How can I modify layer order with the QGIS python API

Typically, after a new_layer = addRasterLayer(...) that inserts new_layer before the active layer, I'd like to move it to the top of the table of contents. How to do it? I use an existing QGIS ...
0
votes
0answers
39 views

How to get the color of a vector layer in pyQGIS?

I have see this topic (How to change the color of a vector layer in pyQGIS?) but I'm looking for get the color not to change. How I can resolve my problem ? Thanks
2
votes
1answer
105 views

QGIS python - identify and highlight features programatically

In QGIS there is an option to select features of a selected layer using a "identify feature" tool. Then the feature get highlighted in a different color and attribute dialog is poping up. like that i ...
0
votes
0answers
87 views

How to programmatically set a rule-based renderer in QGIS?

These days im in a process of developing a plugin , which highlights/change color of set of features in a vector layer depending on some calculation. i found nice article about QGIS – Rule based ...
1
vote
2answers
140 views

How to get the file paths of the loaded layers in a QGIS plugin?

I am very new to GIS, QGIS and Python so please bear with me. I am using QGIS 2.0 and I would like to develop a QGIS plugin that would display the raster layers of the main window in order to allow ...
1
vote
2answers
557 views

How to perform SQL queries and get results from QGIS python console?

I'm writing a python script using QGIS API. I have to get results from postgres database table. The table has geometry field and other non-geometry fields. I want to perform SQL queries on ...
1
vote
1answer
122 views

How to find the polygons bordering a feature programmatically with qgis?

Is there a way to calculate the neighbors of a polygon with pyqgis for every feature? For example, the selected polygons relative to the one in the center: I found this solution, but it's a year ...
2
votes
0answers
83 views

How can i add a north arrow in QgsComposition?

I'm trying to add an svg image of north arrow in QgsComposition using this code: mapRenderer = iface.mapCanvas().mapRenderer() theComposition = QgsComposition(mapRenderer) ...
0
votes
1answer
54 views

Halt QGIS on startup

I have a custom made login form in Python, which launches on QGIS startup. But before the user has a chance to enter the credentials, the program starts normally, bypassing the form. From then on the ...
4
votes
1answer
294 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 ...