Questions tagged [pyqgis]

Python bindings for QGIS.

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5
votes
2answers
2k views

How to add layer/raster with specific position in the QGIS layer list?

I use addRasterLayer(rast,'Name') but this adds the raster to the top. It is possible to set position when I add raster at once? Is it possible??
2
votes
1answer
563 views

How to store attributes of a large shapefile in a list?

I am trying to store the attributes of a shapefile into a list. With following code it works for smaller shapes: addA = [] While provider.nextFeature(feat): attrs = feat.attributeMap() for (k,...
12
votes
1answer
5k views

Writing vector layer to CSV file with geometry using PyQGIS?

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 ...
5
votes
2answers
4k views

Setting up Python 2.7 to work in both QGIS and ArcGIS Desktop?

I have both ArcGIS 10.1 and QGIS 1.8 installed and both include Python 2.7 in slightly different setups and in different folders (c:\Python27\ArcGIS10.1\ and c:\Program Files (x86)\Quantum GIS Lisboa\...
10
votes
5answers
5k views

Calculating Image boundary / footprint of satellite images using open source tools?

I need to create the polygon outlines of several single layer raster images, not the extent/bounding box, but the area without the nodata values, as shown here: Creating shapefile showing footprints ...
0
votes
1answer
125 views

Make many lines in one layer (Python)

I what to create many lines with this code: v_layer = QgsVectorLayer("LineString", "cable", "memory") pr = v_layer.dataProvider() seg = QgsFeature() seg.setGeometry(QgsGeometry.fromPolyline([...
0
votes
2answers
107 views

Python to get ids from shapefile don't return all records

I have some Python code to get the ids and georeference from a shapefile: canvas = qgis.utils.iface.mapCanvas() allLayers = canvas.layers() nos = QgsFeature() for i in allLayers: if i.name()=='...
0
votes
1answer
154 views

How to convert geometry of shapefile to decimals

I try to create a line with two points. These points are obtained in a shapefile layer. How can I convert that points to decimals?
0
votes
2answers
2k views

How to display data from a feature?

I want to display data based on the feature currently selected/clicked on. I am following a tutorial from http://www.qgisworkshop.org/html/workshop/plugins_tutorial.html. It initially shows you how ...
2
votes
1answer
1k views

How to use expression in QgsVectorlayer label by using python?

how to show the two field values as a label on features. I have done it for a field called "ErrorDescr" with this i need to show another field values. Other field is "MarkerId" layer....
13
votes
2answers
16k views

How can I programatically create and add features to a memory layer in QGIS 1.9?

I had a working plugin in QGIS 1.8 which read data from an MSAccess database and added it to a series of memory layers. There is some processing involved in the interim so I don't think simply using ...
6
votes
1answer
3k views

Understanding QGIS API documentation to write Python code using QgsVectorLayer?

I am not sure how to use the API documentation to code in Python. For example, I want to determine whether a layer is a point, line or polygon layer and found the following in the API documentation: ...
1
vote
1answer
2k views

Running a script with QgsFeature from within the console

I am trying to run a script from the QGis Python console (similar to: http://spatialgalaxy.net/2012/01/27/qgis-running-scripts-in-the-python-console/) The line feat=QgsFeature() operates fine from ...
4
votes
3answers
5k views

How to set Marker Line symbol for QgsVectorLayer by using Python?

QgsVectorLayer Right click->Properties->Style->Single symbol->click on simple line in tree node ->symbol layer type -> Marker line Kindly help me to set marker line symbol programmatically by using ...
-1
votes
4answers
2k views

How to make line with arrow head in QgsVectorLayer using python?

I need to draw line with arrow head or after drawn the line i need to make it as arrow head line by using python. or can we set any arrow head symbol for line features by using python? Kindly help me ...
1
vote
1answer
790 views

Open QGIS project with parameters

I am looking at a piece of work to deploy QGIS as the standard within an organisation. There is an existing piece of software that I need to link to QGIS so that when a button is pressed within the ...
5
votes
1answer
7k views

Finding nearest line to point in QGIS? [duplicate]

Given a point and few lines, how should I go about finding the nearest line to the point? I am aware of Finding nearest line to point using ArcGIS Desktop (ArcObjects/ArcPy)?, but that is in ArcGIS ...
33
votes
1answer
7k views

Drawing perpendicular lines in PyQGIS?

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 from ...
3
votes
1answer
3k views

How to “Merge Selected Features” with python?

I have been looking for the answer to this question for some time now, but can't seem to find it! My problem is straight forward: I have one layer It contains lots of features (only polygons), say ...
4
votes
2answers
4k views

Creating QGIS layers in python console vs stand-alone application

I am having trouble creating a QGIS vector layer in a stand-alone python script while exactly the same code works fine in python console inside QGIS. The following code results in a proper ...
8
votes
2answers
5k views

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. # #...
15
votes
1answer
4k views

Is it possible to show our custom message in QGIS Status bar using python?

Is there any way to show our custom message in Qgis Status bar using python? Just like in arcgis IApplication.statusbar.message(0) = "Please wait..." like that is there any option to show progressbar ...
3
votes
1answer
460 views

How to get a message when the map is moved in QGIS?

I want to get a message when every time I move the map. I had: def info(self): QMessageBox.information( self, self.tr( "Info" ), self.tr("info") ) I suppose that used to be something like that.....
16
votes
4answers
14k views

Filter 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 where clause to ...
4
votes
1answer
3k views

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 ...
13
votes
1answer
4k views

How to see print commands through Python Script while programming plugin for QGIS?

Is there a way that from running a custom plugin made for QGIS that a Python Shell can appear along when the plugin is run, like a debug screen? I'm asking this to know if there is a way to see print ...
9
votes
1answer
3k views

Speed of editing attributes in QGIS from a Python plugin

I'm trying to edit the value of an attribute for each feature in a layer using a QGIS Python plugin. I've found that doing this outside of editing mode is much slower than while editing (even ...
3
votes
1answer
2k views

Python Script that calls the Voronoi Polygons Function?

I've been looking to see if there was a way to call Voronoi Polygons function found in Vector/Geometry Tools, directly from the code but I have not found one. Does this currently exist? Is there a way ...
4
votes
1answer
2k views

How to get CRS of a raster layer in pyqgis?

I have this problem accessing to the coordinate reference system(crs) of a raster layer map. I wonder if such thing is possible? I have used this xml from GDAL open map service to load in a raster ...
2
votes
2answers
2k views

Determining coordinates of corners of raster layer using PyQGIS?

How can we determine the coordinates of the corners of the raster layer? The image opens function QgsRasterLayer.
11
votes
1answer
314 views

How to save python session in QGIS?

After running a lot of scripts in QGIS' python console, I have more than 10 dictionaries and lists, and I need these for further analysis. Is there a way to save python session, with all these ...
1
vote
1answer
952 views

How to add MS SQL table using python console?

I have MS SQL Server 2008 R2 database. How to add MS SQL Table using python console in QGIS?
2
votes
2answers
758 views

How to handle adding a PostGIS layer in pyQgis without saving password?

I'm writing python plugin and trying to find the right way to add PostGIS layer on the map without storing user password. After adding layer on the map, I strip out the password from uri like this: ...
12
votes
1answer
1k 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! ...
4
votes
1answer
2k views

How to add one or more points to an existing polyline or polygon?

Using the following code, I make a polyline with two points. vl = QgsVectorLayer("LineString", layerName, "memory") pr = vl.dataProvider() vl.startEditing() fet = QgsFeature() fet....
2
votes
2answers
960 views

How to check if two qgsPoints are equal in PyQgis

I have two points: a=QgsGeometry.fromPoint(QgsPoint(227739,908343)) b=QgsGeometry.fromPoint(QgsPoint(227739,908343)) but when I run: a==b it returns False. What am I doing wrong? Update: it ...
1
vote
0answers
208 views

Saving after using fet.setFeatureId in PyQGIS?

By using the following code, I want to change the id of the line when saving the line. But the setFeatureId command, gives a false when doing the commitChanges(). Any idea how to change the id? vl ...
4
votes
2answers
536 views

How to write an equivalent to MapBasic's CreateLine in pyQGIS?

I know this kind of question has been asked, in part, before - specifically: Seeing QGIS Python Commands and: How is object created as line using createline stored in .tab file? but this is a specific ...
2
votes
1answer
947 views

How to store selected attributes of vector layer using PyQGIS

I'm following this PyQgis workshop: http://www.qgisworkshop.org/html/workshop/python_in_qgis_tutorial2.html#accessing-data-attributes I have a point layer shapefile. I want to be able to retrieve and ...
11
votes
3answers
6k views

Calling clip function in pyQGIS from python console?

Is there a way to call the clip function in QQGIS from the python console? It is found under geoprocessing tools in the vector menu.
3
votes
1answer
1k views

How to calculate all paired shortest path using PyQGIS?

The code for shortest path analysis with PyQGIS specifies start and end nodes explicitly: pStart = QgsPoint( -1.37144, 0.543836 ) pStop = QgsPoint( -1.1027, 0.699986 ) http://www.qgis.org/pyqgis-...
2
votes
1answer
2k views

How to get vector feature by mouse location?

I'm writing a photo grouping plugin. My current problem can be broken up into "end goal" and "baby steps", because I think that's what I want. But if there's a way to get to the end by a different ...
4
votes
1answer
5k views

How to change vector attributes values?

I want to change vector attributes values. i could not get the command fet.setAttribute indeed, it is mentionned in http://hub.qgis.org/issues/7223 that: "The QgsFeature instance now must be ...
5
votes
2answers
3k views

PyQgis overwrite shapefile and adding layer to QGIS

I am creating a shapefile in Python by: driver = ogr.GetDriverByName('ESRI Shapefile') datasource = driver.CreateDataSource('c:/temp/toke2.shp') layer = datasource.CreateLayer('layerName',geom_type=...
9
votes
6answers
9k views

Creating label formatted like “ 1,000' ” from numeric field?

This question builds on a previous question I came across at gis.stackexchange: How to easily edit attribute data using Regular Expressions? Perhaps someone can point me in the right direction? I ...
2
votes
1answer
2k views

How to write a CSV from Python console in QGIS?

I am trying to write out a CSV file from a vector layer made up of points using the python console in QGIS. I've tried the following command: QgsVectorFileWriter.writeAsVectorFormat(layer_Map, Folder ...
6
votes
3answers
2k views

Save a layer for each unique value using Python in QGIS

I have a map, in which each region is defined as an attribute of the map (I can select each region from the attribute table). I am trying to create new layers each one containing only 1 region using ...
8
votes
1answer
5k views

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....
3
votes
1answer
1k views

How to use QgsOverlayAnalyzer class in pyQGIS?

I am very new to Python scripting in QuantumGIS, so bear with me please. I am trying to use the QgsOverlayAnalyzer class in QuantumGIS (http://www.qgis.org/api/classQgsOverlayAnalyzer.html#details) ...
4
votes
4answers
1k views

How to display a “Save As” dialog for raster files?

I'm writing a QGIS plugin in python. I need to show a "Save as" dialog window in order to allow the user to select the path of the output raster file. Do I need to create a QFileDialog and manually ...