Python is an open source interpreted programming language used in many GIS programs.

learn more… | top users | synonyms

1
vote
1answer
187 views

How to add attributes to shapefile with Python and pyshp?

I'm using pyshp for creating a shapefile. I need to populate tens of fields with values using the record() method of shapefile.Writer. I have those values as a list, but have no idea how to send it to ...
0
votes
0answers
63 views

Why don't libgrass.so.1.8.0 and libqgissqlantconnection.so.1.8.0 load?

I have compiled Qgis 1.8 at Ubuntu 12.10, but some phyton plugins does'nt work, like sextante. Trying to solve this problem, some files don't have been load. They are: libgrass.so.1.8.0 and ...
-3
votes
2answers
950 views

What does Runtime error : 'NoneType' object has no attribute '<field_name>' mean?

Here is my code #arcpy import arcpy,sys from arcpy import env env=r"C:\Users\Jaya\Desktop\python_practice" totalRec=arcpy.GetCount_management("river") rows=arcpy.SearchCursor("river") ...
0
votes
1answer
1k views

How can I create a line with three points with Python in QGIS?

I'm new to Python and I'm having some dificulties. I want to create a simple layer with a line in the console of QGIS with Python. How can I do that?
1
vote
1answer
107 views

Setting More Than One Workspace

I have a number of tables that contain known values in a field. For example, I have a soil type table with one field in it. That field contains a list of known soil types. I have another table that ...
9
votes
1answer
3k views

GDAL/Python: How do I get coordinate system name from SpatialReference?

In Python, using GDAL, I've extracted a raster's projection as a WKT string as follows: wkt = dataset.GetProjection() # wkt is ...
0
votes
1answer
1k views

How to use variable field name in arcpy.SearchCursor?

I have code that says fld = fieldName rows = arcpy.SearchCursor(fc) for row in rows: x = row.fld How do I use a variable for my field name in python ArcGIS 10 on windows? Thanks.
1
vote
1answer
186 views

Need python code example - setting a combo listbox to Null

I want to be able to set the value of a field to Null using python, but I get an error. I am using arcpy.CalculateField_management Any help would be appreciated. Rob Smith
0
votes
1answer
539 views

Check if layer is a QGSVectorLayer from Python Plugin within QGIS

I am trying to extend some concepts in the QGIS Workshop tutorial. Basically, I would like to check if the layer is of type "QGSVectorLayer". In the QGIS Python console, I am able to type canvas = ...
2
votes
1answer
409 views

Generate unique ID upon creating a feature?

Looking for a way to generate a unique Global ID within a feature set when a new feature is created. For example, every time a sewer manhole is added, we need to generate a new unique Global ID that ...
1
vote
1answer
156 views

OGR UnionCascaded gives strange lines (flat polygons)

I'm using OGR to perform a union using UnionCascaded. All my polygons have been created by GDAL polygonize which ensures that all polygons follow pixel edges and should therefore align nicely. But I ...
0
votes
1answer
378 views

How to properly add a Python Module to a Plugin?

I've been trying to use a module that is installed in my local version of python, but whenever I open the plugin itself, it does not manage to locate said module. The module in this case is Noise ...
5
votes
2answers
2k views

How to do advanced Python labeling in Arcmap?

Does anyone have a good reference for advanced/complicated labeling expressions in Arcmap? I am attempting to write a Python label expression that would involve multiple label definitions. Here is ...
1
vote
2answers
1k views

ArcMap label expressions with Python

Having trouble here: I'm trying to use python to write selective label expressions. I have several concentrations and depending on its "_Ex" number I either want it labeled red, not red, or not ...
4
votes
1answer
847 views

Using matplotlib to create and export graphs automatically from ArcMap

I am going to start a project soon where, after the data has been processed in various ways, an output jpg showing a graph of the data should be produced. The workflow is as follows: 1. A feature ...
0
votes
1answer
564 views

Use subprocess.call with gdalwrap

I am now want to use subprocess.call with gdalwrap to clip raster from shapfile (in qgis 1.8.0) I use raster→projections→wrap(reproject)to generate command_line below gdalwarp -t_srs "+proj=tmerc ...
0
votes
1answer
602 views

AttributeError: HelloWorld instance has no attribute 'connect'

Here's the code: import sys,os import win32api from PyQt4.QtCore import * from PyQt4.QtGui import * from qgis.core import * import ctypes from PyQt4 import uic class HelloWorld: def ...
0
votes
2answers
353 views

Splitting Shapefiles [duplicate]

I am trying to create a code that will accept the input of a shapefile, and separate each of its features into separate shapefiles into a specified directory location. Can anyone help ? I am trying to ...
2
votes
1answer
160 views

Script to either rotate existing text element or insert graphic element

I have about 300 maps that contain a text element that needs to be rotated. I am pretty new to python but I have heard how great it is. This seemed like the perfect task for python but I have had no ...
0
votes
1answer
86 views

How to buffer increasing/decreasing population zones?

I will find out the difference in population between year 2000 and 2013. I have a feature class file with the population in year 2000 and 2013 that are connected to the municipal number and that is a ...
2
votes
1answer
523 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() ...
7
votes
2answers
236 views

How to use Python modules as data providers in QGIS?

I don't know if it has been discussed in the past. Qgis data providers can only load native compiled libraries (.so, .dll, etc) that offer the required interface. Is there anything blocking to the ...
1
vote
0answers
22 views

Calculate complete spatial randomness using Python [duplicate]

I currently use the csr() function from Splancs for R (http://cran.r-project.org/web/packages/splancs/splancs.pdf) to calculate complete spatial randomness (CSR) points to be used for spatial ...
1
vote
2answers
1k views

How to Add Shapefile with Symbology from Layer File to ArcMap MXD using ArcPy/Python?

Say I have a Shapefile: C:\DATA\points.shp A layer file: C:\SYMBOLOGY\symbology.lyr And a map document: C:\MAPS\map.mxd How can I add points.shp to map.mxd with the properties of symbology.lyr ...
0
votes
2answers
282 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 ...
3
votes
1answer
336 views

TKinter to provide variables

I've been looking for a way to enter a unique field name into an attribute table for up to 40 feature classes. I need the field names to be meaningful, not just 'field1', 'field2' etc. For example, if ...
0
votes
1answer
514 views

psexec remote file execution with ArcGIS Server

This is perhaps going a bit out of bounds, so i'm not confident I'll get an answer. The short of this is that I've created a python script which leverages psexec to start a bat file on a remote ...
3
votes
1answer
642 views

Why is my simple arcpy script failing? (sets raster cell value to null if below threshold value, ArcGIS 10.1)

As mentioned in the title, simple script to set null cell values below three standard deviations beyond the mean: import arcpy, sys, os #Accept input and output raster inRas = sys.argv[1] outRas = ...
5
votes
1answer
539 views

How to access the road graph plugin in python?

I am developing a few scripts in Python for QGIS 1.8 to automate some geo-tasks and one of them would be to calculate the shortest distance from a hospital to each building in a town. I would like to ...
2
votes
2answers
96 views

Raster format to read with python

I currently have a DEM raster stored in an ESRI geodatabase. I've been asked to create a purely python (e.g., no arcpy functions) program that works with the values. Therefore, I need to convert the ...
4
votes
2answers
3k views

Arcpy Insert Cursor not inserting all rows

Good morning all, I have a script here that takes data from a cross-tabulated non-spatial dataset where monthly values are stored in a single table row for a given year and linearizes those data so ...
1
vote
0answers
287 views

How to embed a PDF into an Excel spreadsheet? [closed]

This is what I want to do: Create report using a polygon feature class to output areas of polygons using some logic and the ExportReport() function (This I have accomplished) Create a PDF of the ...
0
votes
1answer
1k views

How can I avoid UnicodeEncodeError when using geoprocessing tools in QGIS?

I have a shapefile, that I want to split with the "Split Layers by Field"-tool. Due to some umlauts (ä,ü,ö) there will be a python error as soon, as the tool reaches a feature with an umlaut. The ...
0
votes
1answer
544 views

python script in modelbuilder: get field value and return boolean expressions

I have problems integrating a python script in a modelbuilder tool. I'm a absolute beginner with python. Maybe there's also an easier way to solve this problem in modelbuilder without using a python ...
3
votes
1answer
1k views

GDAL bindings problem with ArcMap 10.1 Python tool

I'm really getting mad with this. ArcGIS sometimes can be so just...irritating! Forgive me if this question is by any means duplicating this one or similar ones, but I really can't find my way out of ...
4
votes
2answers
1k views

How to automatically reloaded raster layer 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. # ...
3
votes
3answers
1k views

Updating Attributes using Pyshp

Is it possible to update an attribute field in a shapefile using pyshp ? I went through their documentation and all they show is how to create new attribute rather than editing or updating an already ...
0
votes
1answer
303 views

Using the API of QSpatiaLite plugin

I am using the popular QSpatiaLite plugin for QGIS. Since I am creating and modifying SpatiaLite tables directly with Python (using pyspatialite), I wonder whether I can automate tasks such as ...
3
votes
2answers
2k views

How to add a column in QGIS via python

I have a point shapefile and a polygon shapefile in QGIS now I want to use the point shapefile's value add to polygon shapfile(be a column in the end) there are colors with each value and make the ...
1
vote
4answers
770 views

Get vector features inside a specific extent

The problem: I have a very large vector layer with many features and a much smaller raster layer in a defined region. I want to get only those vector features which are within the raster layers ...
7
votes
2answers
4k views

Generating GeoJSON with Python

Hi I want to programatically create a GeoJSON file using polygons from a shapefile but adding attributes from my own application. This is easily done for a shapefile: def ...
8
votes
4answers
1k views

Is there a mapping between OGR and python data types?

I'm writing a shapefile using OGR in python, creating fields on-the-fly from a python data source. Creation of a new field requires an OGR data type, is there a mapping between OGR and python data ...
5
votes
2answers
1k views

Python: How to export Shapely objects to DXF file

Using shapely package for Python how to export the resulting shapely objects such as buffer to a DXF file?
2
votes
1answer
3k views

Find and replace unicode character in a shapefile

I've found several example of script and blog posts on working with unicode characters, but I haven't been able to make anything works so far... It's a little frustrating I have a shapefile encoded ...
0
votes
1answer
261 views

Is it possible to use GDAL to combine (rather than mosaic) rasters

Is there a GDAL command which can combine multiple rasters so that a unique output value is assigned to each unique combination of input values, like the combine command in ArcGIS? gdal_merge seems ...
5
votes
1answer
1k views

How to create a dropdown menu in QGIS Toolbar with Python

I Have a set of some QAction in my QGIS-Plugin and they are created and added to the toolbar like this icon = QIcon(":/action1.png") self.action1 = QAction(icon, u"Action 1", self.iface.mainWindow()) ...
10
votes
1answer
1k views

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 ...
2
votes
0answers
192 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 ...
4
votes
1answer
946 views

Using Gui tools and arcpy.mapping

For a project I want to create a little program that does simple things like export a map from the python command line, but also users are able to edit said map (without having to open arcmap) e.g ...
6
votes
1answer
2k views

Python Script for getting elevation difference between two points

I have several stream segments 1000 Km long. I need to find the elevation difference between two consecutive points of distance 1 Km starting from the upstream to downstream. How can I get the ...