Python bindings for QGIS.

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4
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159 views

Performing buffering and intersection with script in PyQGIS

I wrote a script that performs the intersection of two layers: The first Layer -> layer1, represents the rivers The second Layer -> layer2, represents a set of circular dots distributed in a ...
3
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50 views

How to develop QGIS Plugin to fully run Spatial Queries With PostGIS?

I'm developing a QGIS plugin that fully run spatial queries with PostGIS. Actually I developed all spatial queries wish need some adjustment. I'm looking for some ressources or documents to know how ...
3
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142 views

How to stop a PyQGIS script that has an infinite loop, using the keyboard?

So i wrote a script that does what i want over and over again using a "while True:" in a certain time interval (every 5 seconds using time.sleep(5)). So far so good BUT when i want to stop it i just ...
3
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64 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
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130 views

PyQGIS: How to color raster layer with existing colorBrewerMap

With pyqgis I have added multiple new raster layers to the legendinterface(). Because i like the ColorBrewer style i want to color some of them with the "Spectral" gradient. How can I do this in ...
3
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65 views

How to include external libraries with my QGIS plugin?

I'm developing a plugin which makes use of "networkx" library extensively. However, networkx is not part of Python libraries pre-installed in QGIS. Is there a way to include this library with my ...
3
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120 views

Programmatically selecting features by polygon

Expanding upon this post how could you use QGis to programmatically draw a selection polygon and select features within the polygon? I have been using QgsMapToolEmitPoint(self.canvas), to find and ...
3
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121 views

How can I change the NoData value in QGIS 2.x using the python console

I'm trying to add a NoData value to a single band raster image in QGIS 2.0 using the python console but can't find the right bit of code to do it. Here's what I see on the console: >>> ...
3
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662 views

How to write vector layer to csv file with geometry by PYTHON?

I use Python try to write vector layer file to csv file with this code QgsVectorFileWriter.writeAsVectorFormat(mylayer, r'c:\temp\xyz.csv', "utf-8", None, "CSV") It can export to xyz.csv but only ...
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20 views

PyQgis: How to access a deleted features attributes (before committing)

I have a signal setup for a feature deletion event on a layer: self.layer.featureDeleted.connect(self.feature_deleted) When I try and grab an attribute from the deleted feature on the slot, a ...
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31 views

How to load a style from POSTGIS in PyQt

The thing is that I have four styles I have created in QGIS through the GUI and saved into a postgresql database. I can see them in the table named layer_styles I have seen similar questions asking ...
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29 views

How to rename field names in a shapefile attribute table without table manager using python

By using the table manager we can rename the field names but i want to rename of fields using python. How can i do that?
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19 views

PyQGIS Use of predefined color ramps

I´m trying to apply one of predefined color ramps to a categorized field in a vector layer. To do this, I'm using the code below suggested by Irssvt in another post. However, I cant´t see the result ...
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40 views

How to change the symbology of selected features in QGIS

In QGIS selected features are normally highlighted in a different color to draw user’s attention on the selection. The default color can be changed programmatically. As a nice to have my standalone ...
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34 views

QGIS QgsLayerTreeGroup signal “currentLayerChanged”?

In a pyqgis context, I use the "currentLayerChanged(QgsMapLayer *)" signal of the QgisInterface class to do something when the current layer is changed, but I need now to do the same when I select a ...
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48 views

QGIS not interacting with iface from python class

So I'm working on something where i need to use threads from python console of QGIS. The following line of code adds layer successfully iface.addVectorLayer("D:\ArcGIS Misc\Atlas\points.shp", ...
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80 views

Is it possible to use memory layers in QGIS processing algorithms?

I am building a QGIS plugin that connects to a MySQL database in the local network, and then adds a subset of one of the tables to an in-memory layer; the subset is based on data currency (only taking ...
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102 views

How do I install a external package in QGIS?

Is it possible to install an external package in QGIS? For example: Can I install ReportLab in order to create a plugin to make pdf reports? Or Pandas. How can I install Pandas in QGIS Python ...
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89 views

How to change the group icon in legend via Python in QGIS 2.6?

How to change the group icon in legend via Python in QGIS 2.6? At version 1.x I did it this way: self.legendTree = self.iface.mainWindow().findChild(QDockWidget,"Legend").findChild(QTreeWidget) ...
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139 views

Efficiently generate Voronoi layers in qgis via Python

The following python commands both appear to function when called in qgis 2.6 to generate Voronoi diagrams: processing.runalg("qgis:voronoipolygons", pointLayer, 1, None) ...
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54 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))") ...
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71 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 = ...
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84 views

How to customize the visibility of buttons in QGIS?

The built-in toolbar named "Composer" has an icon "Duplicate Composer". I wish to toggle the visibility of this button in the toolbar. How do I achieve this using pyqgis?
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30 views

How to show combine results or export them with PyQgis

I'm quite new in Pyqgis and i think Pyqgis could make my work easier. I first want to try with a simple code, here is what i want: merge some features and then export them in a shape files. For the ...
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60 views

Using pdb in QGIS console

I am unable to use pdb from qgis console. If I run a function that calls pdb.set_trace() I get the error Traceback (most recent call last): File "<input>", line 1, in <module> File ...
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54 views

PyQGIS: standard and advanced linear referencing possibilities

I'm aware of the existence of the following QGIS plugins: QChainage Event layer linear referencing LRS Although, all of these tools offer some linear referencing capabilities, I find that they ...
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74 views

How to open a second window in QGIS plugin from a button inside the main window

If I already created a qgis plugin, and i need to create a button inside that plugin that opens a new window, how is that possible? Qt creator won't add a slot unless there are a header file. I looked ...
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81 views

PyQGIS cookbook seems out of date

I am trying to follow the http://docs.qgis.org/testing/en/docs/pyqgis_developer_cookbook/ but it seems to be out of date, for example many of the raster methods no longer work as indicated or even ...
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193 views

How to overlay Google Map in a standalone PyQgis application?

I have created a standalone PyQGIS app (within Python itself, not a plugin) with PyQt and PyQGIS API. It generates my map really well. I would like to overlay a Google Map layer as base map just like ...
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141 views

Apply graduated symbology renderer works in Python console but not in standalone script

I use the following PyQGIS script to load a vector layer from a shapefile and apply graduated symbology to it (tried to make it as minimalistic as possible). This works well in the QGIS 2.4 Chugiak ...
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105 views

Iterating between two layers using QGIS python

I will try and explain my situation as clearly as possible. I just created my first plugin that is being used to analyze between various layers and give back quantities to the user. Most of it is ...
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94 views

How setup python path in my ide to recognize QGIS API

I'm using Intellij with python plugin. Classpath for python contains $QGIS/apps/qgis/python but my ide not recognize eg. QgsVectorLayer. Any additional entry is required?
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135 views

PyQGIS add WMS layer with CQL_FILTER

Dear PyQgis developers! I'd like to add a wms layer through my QGIS plugin with custom CQL_FILTER parameters. My problem is, that the CQL_FILTER parameters are not passed to the GeoServer (I can see ...
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192 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 ...
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111 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 ...
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65 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 = ...
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70 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 ...
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68 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 ...
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94 views

developer problem with PyQGIS

I am a QGIS developer. We have been modifying the source code of QGIS for several months and have done good work in QGIS version 2.1. After that we tried to do the same modifications for QGIS version ...
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166 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 ...
2
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0answers
147 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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153 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) ...
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93 views

Is there a way to build topology and work with topology relations in PyQGIS?

Is there a way to build topology and work with topology relations in PyQGIS? I'm asking because I need to run some custom generalization algorithms on my data, and I need to preserve topology. ...
2
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108 views

PyQGIS - Converting WKB to String

Using PyQGIS, i'd like to print the string representation of a point WKB (like what PostGIS displays in geometry columns). For example: p = QgsGeometry.fromPoint(QgsPoint(2, 4)) wkb = p.asWkb() print ...
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257 views

How to render a transparent raster layer on top of one or more vector layers with PyQgis?

I been trying to render a map with a 3 vector layers and one raster layer. The idea is that the raster layer should be on top of the other 3 vector layers. The problem is that even when I add the ...
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195 views

qgis python app how to add edit feature button?

I'd like to develop a QGIS Python app for plotting points and editing the attributes. I've started with the tutorials here: http://blog.qgis.org/?q=node/59 and read the cookbook ...
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65 views

How to delete a point with known coordinates in python?

I was wondering if there is a piece of code that does the opposite that setGeometry does and removes a point if there is one at x and y coordinates?
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455 views

Qgis Plugin development with postgres data

can someone help me with initial developing on qgis plugin that displays postgres data table on a QTTableView or QTTableWidget? So far: I can connect to database using psycopg2 or using ...
2
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280 views

no module named core

Hi I am trying to access and use QGIS modules/class/methods from IDLE on a mac. I have had the same problem as a few other people, and browsing the forums have tried to follow the advice they have ...
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754 views

How to change feature's geometry?

Hy, I'm creating my layer like this: crs = core.QgsCoordinateReferenceSystem(4326, core.QgsCoordinateReferenceSystem.EpsgCrsId) uri = "Polygon" uri += '?crs=' + crs.authid() uri += ...