Python bindings for QGIS.

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No expected output when accessing variable from one function and using in another fucntion

I have a function say selectedfeatures this function would be called when a selection changed event happens in mapcanvas. self.canvas.selectionChanged.connect(self.selectedfeatures) ...
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47 views

How to define an event for features selected in mapcanvas in qgis using python

I have created a push button, when it is clicked it calls the function 'selectfeatures'. This function will call the Select feature by free hand tool of QGIS and allows the user to select features in ...
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52 views

How to replace VectorWriter with QgsVectorFileWriter?

Within QGIS 2.8.1 I found within the Processing Toolbox a script called "Points on crossing lines" which should exactly as it is named. Unfortunately it needs processing.core.VectorWriter which I ...
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18 views

QGIS plugin : connect to polygonselect Maptool signals

Working on a new plugin I am trying to connect a custom function to the mouse right-clic signal while using the polygon selecting maptool. I have activated the maptool through : def run(self): ...
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43 views

Setting Scale Dependent Visibility for WMS in PyQGIS

This code imports 'MiniScale' mapping from my WMS miniScale = ...
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42 views

How to store a triggering action and events and call them when needed using python in qgis

Can anyone explain in detail how to store the triggering action or an event that take place in the mapcanvas in a variable and call the same when needed in python. Say for example,say i have ...
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51 views

How to import the “QGis” class in a script?

I want to check which type of geometry the current layer has. Therefore I use the PyQGIS documentation on Access to Geometry and my code looks like: if iface.mapCanvas().currentLayer().wkbType() == ...
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2answers
65 views

Is it possible to sort the features by an attribute programmatically?

I have written a PyQGIS script that loops through an attribute table and finds duplicated values in a target attribute field. My technique requires that the attribute table is first sorted by the ...
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1answer
65 views

How to access a specific feature?

Is it possible to go to a specified row number (or perhaps the next/previous) row using PyQGIS? This code gets the value of the first attribute in the first row of the table features = ...
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32 views

Initalize plugin with current working directory?

Upon starting Qgis, a (currently under construction) plugin needs a means of checking the current project/legend/registry. This checksum would ideally occur upon startup automatically. As the plugin ...
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46 views

PyQGIS: Is it possible to replace an action triggered script by one supplied through a plugin?

In ArcView 3 all controls (menu choices, buttons, tools) had scripts associated with them that could be changed simply by supplying a script with the same name through an extension (plugin). That way ...
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110 views

Batch add column to layers and add layer prefix in PyQGIS

I have a number of layers each with a prefix like A_ B_ and so forth. I'd like to: Add a column (text) called DENSITY to each shp Add the prefix letter from the layer name to each row in the ...
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114 views

“ImportError: no module named qgis.core” in standalone app

I am developing a standalone app (in Windows) using libraries from QGIS. When I run the script in cmd, I get the ImportError: no module named qgis.core. I read in several posts that I need to ...
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51 views

Plugin to run one function when run button is clicked

My plugin gui is attached below which has two functions one is selecting state, cities from the combo box and distance to be entered in the lineedit and the other is if we click a pushbutton it will ...
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63 views

Go through items in a composer legend (QGIS 2.6)

I'm trying to develop a plugin in QGIS 2.6, which opens a composer, add a map and a legend, and (among other things) adjusts the legend. Is there a way to go through items in a composer legend with ...
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2answers
56 views

How to get a layer that is not active with PyQGIS

I want to retrieve attributes of selected objects on a layer with PyQGIS. All example I see is for the active layer: vlayer=qgis.utils.iface.activeLayer() selected_bf = vlayer.selectedFeatures() ...
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49 views

How may I use Umlaute programmatically to show up correctly in PyQGIS messagebar?

So far I couldn't figure out how to write something like u"Einstellungen aus ArcView übernehmen" to show up correctly as the titel of my messagebar. At least I can save my source (although this seems ...
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21 views

Refreshing QGIS view [duplicate]

I've written a short python script for use in QGIS (currently using 2.8.1) to set the CRS for all loaded layers to OSGB 1936 / BNG. The script correctly sets the CRS but I have to manually scroll ...
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44 views

Trouble buffering a vector layer in QGIS with PyQGIS

I am working on a script that imports a .csv layer that has lat long coordinates, which I then want to buffer in feet. I've created a vector layer from the .csv file and tried to set the coordinate ...
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26 views

How to activate the cursor once we deactivated by activating panning tool

We have activated pan tool on canvas using the following command: canvasPressEvent(self,event): if event.button == 1: qgis.utils.iface.actionPan().trigger() canvasReleaseEvent(self,event): ...
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31 views

List printing same values as a buffer output instead printing unique values

I have a list of features selected in the mapcanvas and for that selected features i am doing buffer and printing the feature names that are inside the buffer. While printing,all values in the list ...
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1answer
40 views

How to add point features with coords taken from a .txt and show them on the map canvas?

Ok, so i am on Windows 7 and using QGIS 2.6 and i have a .txt file with some simple coords. I have extracted the coords to a list, no prob with that. But i looked at the PyQGIS cookbook on how to add ...
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81 views

How to access checked layers in PyQGIS?

qgis.utils.iface.activeLayer() accesses the current active layer, but I would like to get all checked layers in the QGIS ToC. How can I do it?
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64 views

Convexhull for selected features and performing buffer for the resultant convexhull using python

I have features selected on the mapcanvas. I want to perform convex hull for those selected features and save those in a memory or store it in a variable preferably and then want to do buffer for the ...
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61 views

How to install pygame or Tkinter for QGIS Python?

So i have downloaded pygame and installed it. Now i want to write scripts and run them through the QGIS console that implement methods of pygame but when the console reads "import pygame" i get a ...
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59 views

Save Vector layer and update .qgs project file (pyQGIS)

need help to solve the following use case: QGIS started with new project (no layers) New layer is created programmaticaly and data is populated: vl = QgsVectorLayer("Point", "temporary_points", ...
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17 views

Labels not displaying when rendering to image with pyQGIS

I'm using the simple example in the pyQGIS cookbook http://docs.qgis.org/testing/en/docs/pyqgis_developer_cookbook/composer.html I'm able to manipulate the features in my layer using Python, but the ...
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63 views

How to programmatically close a QMessagebox without clicking ok or X? [closed]

So part of my script in PyQGIS is this: QMessageBox.warning(None,"Warning","bla bla bla") The box apperas just fine but i want it to close after a few seconds so i am looking for something like ...
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26 views

How to apply Zoom Extent from several QgsVector layers with Labels in PyQGIS?

I have the following case: Project constists of three layers: Open Layers plugin with Google streets QGSVector layer with Point features and Label enabled QGSVector layer with Polyline features and ...
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70 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 ...
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43 views

How to reload a raster file from the python shell

I do this in the QGIS python shell: # get the raster file (and data) of the active layer canvas = qgis.utils.iface.mapCanvas() rLayer = canvas.currentLayer() rLayerPath = ...
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81 views

How to change the edit widget for fields in a layer with PyQGIS?

Is possible change the edit widget with PyQGIS? I have made an extension that loads a PostGIS layer and I want to edit the date fields with the date widget by default without any change in the ...
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46 views

Why this Python script only works once on QGIS?

So i have this script to change the color of some specific features(lines) using categories in a vector layer. When i import the script the console in the first time through the console it works just ...
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25 views

QGIS get the X and Y of a raster file by click

I have a raster file (Geotiff) and try to write a plugin that can change the value of one cell in a raster (== array cell). I know how to get a QGIS point but how can I get the array index from on ...
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37 views

How to change the color of a specific feature(s) with a PyQGIS script

First of all im a big noob so don't hate. So image that the lines that i have drawn is simple pipeline network, represented by some simple lines in a vector layer. Now the question is, how can i ...
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48 views

PyQGIS plugin debugging from Eclipse

having trouble with debuging QyPython plugins from Eclipse: - Win 7 x64 - QGIS 2.7 - Eclipse Luna with PyDev installed Tried to debug using Remote Debugger ...
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43 views

Creating Convex hull and finding buffer in QGIS

I have a layer and features are selected using Select Features by freehand tool and for that selected features, convex hull was done and for that convex hull i am trying to find buffer and write it in ...
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41 views

Buffer for features selected in the mapcanvas and writing to csv file

I have some features selected by using "Select Features by Freehand" tool in QGIS and try to find the buffer for those selected features alone and write the city and state names within in the buffer ...
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1answer
68 views

Use raster memory layer from QGIS processing result

I want to apply subsequent QGIS raster processing algorithms in a python script. I want to use memory layers for intermediate calculation results since I am only interested in the end result. As ...
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1answer
45 views

Odd behavior in a QGIS plugin: my function is triggered twice

I have a plugin with a function (triggered by a button) that selects a specific layer by name, then shows its attribute table. When I close the plugin and open it again, the attribute table pops up ...
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1answer
35 views

How to select from selection with PyQGIS?

The expression box has a handy "select from selection" button. Is there a way to emulate this with python? I have the basic expressions down, but can't find a way to do this.
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39 views

How to do a buffer operation for a polygon drawn by the user using python in QGIS

I have a polygon drawn on the map canvas.Say the polygon would be drawn by using "Measure Area" tool in qgis.Now, I want to do buffer for certain distance around that polygon.I can see the below ...
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25 views

Warning message needed when there is no specific layer instead of python error

In my plugin, when I click a button it will call the findTheCityNames function which is attached below and get features if there is a particular layer. What I want is if there is no specific layer in ...
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59 views

How to get a layer by name in PyQGIS?

I have a plugin which finds buffer for list of cities, provided the distance. The state and city names are taken from the attribute table and gets filtered accordingly. What I want is My plugin should ...
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1answer
52 views

Global name canvas is not defined

I am just trying to print the layer name using python in my QGIS plugin by following code. allLayers = canvas.layers() for i in allLayers: print i.name() It is saying an error: Global name canvas ...
2
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1answer
63 views

PyQGIS load dxf file as a vector layer

Can somebody help me with loading a dxf file as a vector layer with PyQGIS? Is QgsDataSourceURI an option? I've tried it with this code, but it didn't work. fitxer="/tmp/prova.dxf" uri = ...
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22 views

Vector Layer Symbology Export?

When programmatically creating / saving a QgsVectorLayer - implementation of the ExportSymbology functionality does not seem to exhibit the implied effects. Does such a command not indicate that the ...
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1answer
64 views

Cannot rename output file using standalone script for QGIS

I would like to rename all output files after my script has finished processing them by adding "(A)" after their file name (eg. Layer.shp -> Layer (A).shp). I received an answer from this post on the ...
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33 views

How to select the buffer region in map canvas in my plugin using python

I am developing a plugin which finds buffer by getting state name, city name and distance given by the user. The plugin works fine and writes the cities that matches the distance in a CSV file. What i ...
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66 views

How to add label to QgsVectorLayer by Python

my goal is to define label programmaticly for the case similar for the figure below: But didn't find any guidance how to do so using Python. I have a feeling it could be done using QgsLabel but ...