Python bindings for QGIS.

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5
votes
0answers
429 views

PyQGIS CRS on the fly reprojetion

As a first step of a pyqgis plugin I'm trying to import several shape files at once. To get them aligned, using the GUI, I'd enable on the fly reprojections and set the project crs to WGS84. I'd then ...
3
votes
0answers
13 views

Error writing buffered memory layer to shapefile in QGIS

I have created a memory polygon layerin my QGIS plugin. Then I added a buffer based on a point. I can see the ploygon layer in the map canvas and I can save it to a shapefile from the main GUI. But ...
3
votes
0answers
41 views

PyQGIS: Trying to export layer to shapefile

I´m using python in QGIS 2.2 and struggling with an error trying this: # create layer from text _vlayer = QgsVectorLayer(_ur1, "raw", "delimitedtext") works fine but: # export layer to shape ...
3
votes
0answers
68 views

Find Polygon in “Layer A” containing Polygon in “Layer B”

I haven't found yet someone with the same problem, so I'm posting a new question. The topic seems quite standard, so I'm sure there's a way to do it in QGIS. I have two layers: Region Layer Postcode ...
3
votes
0answers
100 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 ...
2
votes
0answers
20 views

How do the architecture in qgis plugin creation is linked with eachother using plugin builder?

I am just trying to understand how the architecture or the workflow is linked each other while QGIS Plugin creation using plugin builder. It would be better for me to understand if anyone explains ...
2
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0answers
25 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))") ...
2
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0answers
43 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 = ...
2
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0answers
42 views

Via PyQgis how to refresh a modified CSV layer without having to reopen the file?

UPDATED: With an CSV layer Qgis workspace [loaded as a delimited text layer], an external algorithm is ran; outputting (writing) new values to certain rows in the layers source CSV file. The writing ...
2
votes
0answers
58 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?
2
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0answers
35 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 ...
2
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0answers
35 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 ...
2
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0answers
41 views

How to load all items from a template with pyQGIS in QGIS 2.6

Since QGIS 2.6, the LoadFromTemplate method seems not work any more (or works differently?) This is my code to add items in my composer from a template : self.composition = ...
2
votes
0answers
68 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 ...
2
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0answers
28 views

How to make added toolbar buttons exclusive?

I've added a toolbar to the QGIS mainWindow. Also I've added some checkable buttons to the toolbar. How can i now make my checkable buttons untoggle on QGIS default toolbars' checkable buttons press ...
2
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0answers
71 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 ...
2
votes
0answers
42 views

Assigning Color Ramp using PyQGIS

According to the PyQGIS Cookbook, a color ramp can be assigned in the following way: rlayer.setColorShadingAlgorithm(QgsRasterLayer.ColorRampShader) lst = [ QgsColorRampShader.ColorRampItem(0, ...
2
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0answers
70 views

How to get user and password of a PostGIS layer

I wonder if it is possible to get the user and password for a PostGIS database if they are stored in the PostGis connection information. I get the connection information at the moment from the ...
2
votes
0answers
47 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?
2
votes
0answers
23 views

Refreshing “layer render order” widget

i made changes in the render order of my map canvas using a : qgis.utils.iface.mapCanvas().setLayerSet(a) "a" being a list of QgsMapCanvasLayer My code is working as expected (i see result on map ...
2
votes
0answers
47 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 ...
2
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0answers
38 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 ...
2
votes
0answers
52 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 = ...
2
votes
0answers
51 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 ...
2
votes
0answers
49 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 ...
2
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0answers
102 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 ...
2
votes
0answers
75 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 ...
2
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0answers
126 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: ...
2
votes
0answers
97 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? ...
2
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0answers
115 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) ...
2
votes
0answers
86 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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0answers
81 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 ...
2
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0answers
216 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 ...
2
votes
0answers
255 views

PyQGIS joining a dbf to a shapefile

I am trying to join a shp and dbf file using the PyQGIS API. The code I'll use is below: from PyQt4.QtCore import * vector1 = QgsVectorLayer("path to dbf file", "test1", "ogr") id1 = vector1.id() ...
2
votes
0answers
235 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 ...
2
votes
0answers
157 views

Setting border-style to 'no pen' using QgsGraduatedSymbolRendererV2

I am developing a QGIS plugin that, after a series of inputs, will produce a thematic map using the QgsGraduatedSymbolRendererV2. Because the polygon are very small, the boarders make it such that ...
1
vote
0answers
18 views

Error while creating QGIS plugin

I tried developing a python plugin in QGIS2.6 following the instructions in the link http://anitagraser.com/2014/04/26/getting-started-writing-qgis-2-x-plugins/.When I launch the plugin in QGIS after ...
1
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0answers
36 views

How to change values in a raster file at particular positions?

I have a collection of coordinates which comes from a QGSGeometry object. The shape is a polygon. example: qgsGeometry [[(75.2172,17.6566), (75.8499,17.9613), (75.5218,17.2113), (75.2172,17.4574), ...
1
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0answers
19 views

How do I step into the C++ functions from an external Python app I'm debugging?

I just wanted to see how to step into the C++ class QgsVectorLayer()'s methods from the python call to QgsVectorLayer(self.uri.uri(),'foo','postgres'). I'm trying to debug and it trying to step into ...
1
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0answers
18 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 ...
1
vote
0answers
35 views

Why must I write `geometryType() == 3` for point and polygon shapefiles?

I am asking this question based on the result I received from this earlier post. The following script only works if I set geometryType() == 3 as that is what is being printed out in the Python console ...
1
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0answers
35 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 ...
1
vote
0answers
28 views

How to get the last edited feature id using python

After merging the two features in the polygon the feature id will be changed for the merged feature after committing the changes. So how do i get the feature id of the merged feature or the last ...
1
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0answers
86 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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0answers
89 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 ...
1
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0answers
41 views

Highlight the selected feature with different colors

Is it possible to change the color of a selected feature in qgis 2.2.0 Valmiera? To highlight a feature I use: aLayer.Select(feat.id()) box = vlayer.boundingBoxOfSelected() ...
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0answers
53 views

Error Loading Layer/Shapefile in a Standalone Python QGis Application

I tried loading a shapefile on Python using PyQgis API but to no avail. I double-checked the path to shapefile and found it to be correct. QGIS module also seems to be imported just fine. When I ...
1
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0answers
37 views

Arcpy and pyqgis on same IDE

I have question: is it possible to set up arcpy and pyqgis on the same IDE (I use Pycharm). I have some problem with running my pyqgis scripts from pycharm. When I first configure Pycharm to recognize ...
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0answers
68 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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0answers
79 views

How to change color ramp in graduated classification with standard deviation using pyqgis

I'm using graduated clasiffication with standard deviation to style my shapefile (see code below). But I need to use different color ramp for classes below mean (-1std, -2std etc.).I'm thinking of ...