Python bindings for QGIS.

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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 ...
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1answer
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Problem with import qgis.core when writing a stand-alone PyQGIS script

I am trying to write a stand alone python script in windows 7 that uses qgis.core and various other qgis libraries. I have found an old question on this subject here: How to write standalone Python ...
26
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1answer
3k views

How to draw perpendicular lines in QGIS?

I have a situation like this: What I need to do is to connect each point to every line that is at most, let's say 200 m, away from the point. In other words, I need to draw a perpendicular line ...
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2answers
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How can I access `processing` 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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How to install 3rd party python libraries for QGIS on Windows?

How can I use 3rd party libraries on QGIS plugins on Windows? I've developed a plugin that uses rasterio and numpy for a customer, but he's having problems installing rasterio and numpy. Actually ...
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1answer
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Is there a way to access QGIS plugins in Python?

Is there a way to access QGIS plugins in Python? I'd like to write a script to do some geoprocessing, and I'd like to use the clip, regular points and convex hull tools in fTools, as well as the Road ...
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2answers
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How to automatically reload raster layers if source is changed in QGIS?

How to automatically reloaded raster layer if source is changed? (The path is the same but inside source file are changes) I use: qgis.utils.iface.mapCanvas().refresh() but layer not refresh. # ...
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How to create a new empty vector layer programmatically?

I am new to python and QGIS. I have looked at a few tutorials of python scripts for QGIS. All of them create new vector and raster layers with some existing data source. eg. shapefile or geotiff or ...
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How to evaluate raster calculator expressions from the console?

How can I execute from the console an expression that should be used with the raster calculator? I'm searching for something like this: qgis.someRasterCalcClass.evaluate("boh@1 + boh@2", "outputfile....
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1answer
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Using in-memory vector layer with QGIS processing / SEXTANTE

I'm trying to run the qgis:clip algorithm from console, but am getting an error when using an in-memory layer as the overlay parameter. Is this to be expected, or am I doing something wrong? Code: ...
3
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1answer
642 views

Export several files at the same time in QGIS

I have a lot of .TAB files open in QGIS and I want to save them to .SHP so I can work with them in ArcMap. Is there a way to save/export all these files at the same time or do I really have to "save ...
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1answer
987 views

Is it possible to programmatically add calculated fields?

In the Memory provider described in PyQGIS Cookbook or in question How to create a new empty vector layer programmatically? I can see how to create a vector layer programmatically using standard ...
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Standalone applications using QGIS and environment variables

I've tried going through IRC to see if people can help me out with this, but the medium seems a little clumsy for making any answers clear, so I'm going to try this instead. I would like to program a ...
5
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2answers
804 views

How to add a legend to a canvas in a standalone PyQGIS application?

I am trying to develop a standalone PyQGIS application. The map display does not pose any problems, but I do not know how to add a legend to the canvas.
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2answers
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Programmatically load composer from template and generate atlas using pyQgis

I Am trying to build a plugin to load a print composer from file, generate an atlas and export to image. So far I have been successful in loading the template and exporting it to image. I have been ...
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1answer
736 views

How to call the interpolation plugin from the python console?

I would like to call the QGIS interpolation plugin function (TIN method) (Raster->Interpolate) from python console. I can't find the corresponding function within QGIS API or within the ...
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2answers
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Get a pixel value

How can i do this operation: I want to get a pixel value fro the satellite image (Landat, GeoTIFF, 7 bands) using qgis-python. What operators should i use? (for example in qgis's Python Console)
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2answers
902 views

Using PyQGIS, ArcPy, NumPy, SciPy Together in Windows Command Prompt

I ran across this slight issue when I was looking to access python installations from ArcGIS, QGIS, Anaconda (cited because SciPy & NumPy come with it), and version 2.7 vs 3. Sometimes, I find it ...
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2answers
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How to delete column/field in PyQGIS?

How to remove or delete column fields in a shape file using python?
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4answers
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QGIS 2 Python error on Mac OSX

Have just installed newly released QGIS 2.0. I installed the gdal package available at the official kyngchaos site. It seems to run ok, but when the program loads up I get a lengthy error message ...
3
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1answer
626 views

WMS layer in a QGIS 2.4 stand alone Python script

What is the best way to add a WMS layer on a map, in a stand-alone python script with QGIS 2.4? The methodology explained at the bottom of the official QGIS documentation page seems to be outdated and ...
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1answer
191 views

Failed to create memory layers in QGIS application on Linux

I have written a python class which reads properties of map layers from an XML file and creates appropriate memory layers. I have developed and tested this code with QGIS 2.8.2 on a Windows 7 machine (...
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4answers
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How to get features based on their attributes using Python?

How to Get features by their attributes (similar to Iqueryfilter in arcobjects) in Qgis using python? Instead of getting all features and filter it manually, is there any option to use whereclause to ...
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1answer
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How to find the nearest line to a point in QGIS? [duplicate]

My question is that given a point and few lines, how should I go about finding the nearest line to the point? I am aware of How to I find the nearest line to a point?, but that isin ArcGIS and ...
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1answer
952 views

How to address the new “Task-Completed” QgsMessageBar in Python?

I am really amazed what huge steps the QGIS development has taken in the last months. The new iconset, the improved Print composer and many more changes to be seen in QGIS 2.0 are really awesome! ...
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How to use map composer in a stand-alone script?

I'm trying to follow the map rendering section from the pyqgis cookbook, but I'd like to test this as a standalone application. I can do the first part, using simple rendering, but I'm a bit stuck ...
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How to buffer in pyQGIS?

I'm looking for some examples to do simple python scripts in QGIS. How would I do a buffer analysis on a dataset? I can't seem to find much in the manual and QGIS python that quite matches the Esri ...
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3answers
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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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1answer
151 views

Assign shortcut to a script?

Is it possible to assign a keyboard shortcut to a (custom or not...) script of the Processing Toolbox in QGIS? Haven't found any information about it...
3
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1answer
1k views

Getting dataProvider from vector layer outside QGIS

I'm using PyScripter to explore PyQGIS API because of it's very handy auto-completion function. I've managed to get a handle on a PostGis vector layer by: >>> from qgis.core import * >&...
3
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1answer
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Joining table to shapefile with pyQGIS

Joining shapefiles is a relatively straightforward proess in QGIS using 'add vector join' in the layer properties menu. I can add a csv file as a vector layer, as well as a shapefile, and join the two ...
2
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1answer
416 views

What is the purpose of some functions and files in QGIS Python plugins?

I'm just trying to understand the architecture of a QGIS Plugin created with the QGIS Plugin Builder, as well as the workflow and the linkage among generated files. If possible, I'd prefer a diagram. ...
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3answers
982 views

QGIS install on Ubuntu 14.04 fails

Following the QGIS installation guide I have tried both UbuntuGIS and QGIS stable, but both fail with the error message: The following packages have unmet dependencies: python-qgis : Depends: python-...
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3answers
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Rendering and Labeling Shapefile with PyQGIS

I've been running into a few problems working with the QGIS API for python. I've gotten more comfortable working in the python console in QGIS but I run into problems when I try to run the code ...
4
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1answer
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Does mapCanvas().refresh() not work in QGIS 2.6?

Before I used the function qgis.utils.iface.mapCanvas().refresh() to reload the map canvas after for example a layer color was changed from a plugin. But this is not working with QGIS 2.6 for me. ...
3
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3answers
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How to add QGIS Python API Intellisense support in Aptana Studio3/Pydev

I'm developing QGIS plugins using PyDev in Aptana Studio 3 and I would like to know if it's possible to make it aware of the QGIS API and add some "intellisense" functionnalities when programming. For ...
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2answers
927 views

Join table field with shapefile programatically (via PyQgis)?

The following is currently unsuccessful at fulfilling a table field join to a point shapefile in Qgis. All instances of the join object will print the proper values, and no error is flagged when ...
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1answer
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How to label vector features programmatically?

I am using python for QGIS 2.0.1 and I have a vector layer of points representing the positions of state labels. I want to display the 'state abbreviation' attribute on the corresponding point for ...
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3answers
133 views

Is there any way to freeze the layer names in the TOC?

I would like to freeze the names of layers in TOC. Is there any way to do this via QGIS config or PyQGIS? I´m using QGIS Wien.
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1answer
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When iterating over a vector layer with pyqgis, how do I check whether a feature is selected?

While iterating over a vector layer using the following code (summerized from the example in the pyqgis cookbook), is there a way to check whether a feature is selected? provider = vlayer....
6
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3answers
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How do I set layer transparency in QGIS 2.0 with Python?

I have a raster layer loaded in QGIS and I'd like to be able to set its transparency via the Python console. I'm new to the API and have not been able to find out how to do this. Any help would be ...
3
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1answer
972 views

How to update data from external table in real time?

I have been trying for a long time to connect a external table data[csv] through Excel (for exmaple) with QGis with the objective to each time i change any data in table(for example data location - ...
3
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1answer
963 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 ...
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2answers
277 views

Running PyQGIS script directly (without using interface)?

I wrote the following script, which runs fine from the QGIS python console (it loads two shapefiles, intersects them, and then finds the areas of the new regions): import qgis.utils import qgis.core ...
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2answers
316 views

How to iterate over layers and export them as PNG images with PyQGIS in a standalone script

I would like to export specific layers as a png from a QGIS .qgs map. From the table of contents the script would first export the "boundary, climits, and Div1_Irrig_1956_0" layers as one png. The ...
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1answer
86 views

pyqgis traversing subgroups and group layers

I am trying to find the name of subgroups using pyqgis. I have been trying to use Playing with subgroups I am however unable to traverse and get the names of the subgroup. I have tried the code on ...
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1answer
713 views

How to obtain rotation field name defined in the Labels “Data Defined” section in pyqgis?

I'm trying to find how to get with the QGIS Python API the layer field name that contain the rotation angle used by a layer to rotate its labels? I know that I can obtain the field name containing ...
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3answers
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How to efficiently access the features returned by QgsSpatialIndex?

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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1answer
615 views

Adding new menu item to QGIS Desktop app?

I need to add new menu item to the top level menu of QGIS Desktop (2.7.0); I.e. it shall be on same level as "Project", "Edit", "View", "Layer" etc. As far as I know there is pretty nice way how hide ...
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What are QGIS Arcpy Equivalent Functions for Update/Delete Row/Field?

I am trying to reprogram some scripts from arcpy to qgis (1.8 or 2.0) and there are some simple functions that I want to be able to redo but unfortunately documentation in qgis is lacking in certain ...