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

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5
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2answers
38 views

How is the data access cursor performance so enhanced compared to previous versions?

The data access module was introduced with ArcGIS version 10.1. ESRI describes the data access module as follows (source): The data access module, arcpy.da, is a Python module for working with ...
0
votes
0answers
8 views

How can I efficiently use a list comprehension on an ogr.layer inside a loop in Python?

Problem statement I'm using python 2.7 and ogr 1.11.0 on Windows 7. I have two shapefiles: one for streets and one for junctions. The streets shapefile has fields listing the IDs of the start and ...
3
votes
2answers
245 views

Multiprocessing issues with ArcPy

I am using ArcGIS 'watershed' routine in a script which makes use of multiprocessing. This works fine, but during execution I get the message: Unable to remove directory. Possible causes: 1- Not ...
1
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2answers
117 views

AttributeError: 'int' object has no attribute 'save'

I am trying to use a conditional statement to generate a raster with binary values from a raster with probability values (floating point raster). This is easily done within ArcMap by batching the ...
1
vote
1answer
21 views

Pyqgis 2.2 : How to allow editing on layer and features

I'm writing a pyqgis plugin with qgis 2.2 I succeeded in accessing and displaying vector data (geometries & attributes). Now I would like to allow editing for all my layers and all features ...
4
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1answer
665 views

Interpolating Maps - Statistical Learning Techniques vs Spatial Statistics Techniques

I have recently begun experimenting with the interpolation of variales over a whole country. I have good sized training set where I have several dependant variables (continuous and categorical) ...
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0answers
13 views

How to use the 'if' function to set field value based on various other field values

I am trying to populate a field with a value from another field in the same row, the condition I have set for this to take place is if a third field is equal to 0. In order to achieve this I have ...
3
votes
1answer
236 views

Python SQL connection causes crash in ArcMap

I have the following code which I have striped down to just included the part that is causing a crash in ArcMap. import pymssql # Connect to the Research db using Windows Integrated Authentication. ...
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2answers
23 views

Debugging SQL in arcpy.da.SearchCursor RuntimeError: An invalid SQL statement was used?

I am going through a python script in arcpy 10.1 to Select a field value (i.e. NEAR_DIST) based on three condition as 1) NEAR_DIST<=radius(i.e.500 or anything from user input) 2) ...
1
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1answer
34 views

Automating polygon mergers with python

This is the first real world python program am trying to write. I am trying to create a scrip that takes a shapefile that has n polygons with an integer formatted date (e.g. yyyymmdd or 6/24/2014 is ...
0
votes
2answers
295 views

problems with py2exe, shapely and fiona

I have a short python script, called test: import fiona with fiona.open("C:\\Essai_compil", 'r') as l_Obs_shp: for shp in l_Obs_shp: print shp['geometry'] I want to compile with ...
0
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2answers
277 views

Python Error while Publishing mxd ArcGIS 10.1

I was in the process of publishing my mxd , I had reached till the analysis step where I encontered the error at staging the service. Before this below mentioned code I had created a connection ags ...
2
votes
2answers
644 views

OSR Python testSR.ImportFromEPSG(4326) returns empty spatial reference

This is empty using Python .ImportFromEPSG(4326): import osr #this fails: testSR = osr.SpatialReference() testSR.ImportFromEPSG(4326) print testSR.ExportToPrettyWkt() #why did the import from EPSG ...
0
votes
0answers
22 views

Read large raster into lat/lon value pair to csv file using python and/or gdal?

I have rasters for all of the states in US and they are in 10m resolution. So they can be very large, containing a large number of pixels if you think of TX or AK. I want to create a csv file with ...
2
votes
1answer
35 views

How to return end of string up to a certain character using Field Calculator?

I am trying to accomplish this task: http://stackoverflow.com/questions/15851568/how-to-get-the-last-part-of-a-string-before-a-certain-character within the Field Calculator. I have the below but ...
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0answers
36 views

ArcPy Multiprocessing 000714 - Working in Debug Mode

In an attempt to render an interactive window via matplotlib I am using an out of process script in a toolbox. If I debug the script, it is possible to step through and render the window as expected. ...
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0answers
25 views

How do you duplicate a point within a shapefile using Python?

How do you duplicate a point within a single feature class using Python? I have a partial sample script below, but in a nutshell, I want to duplicate a point, copy it into the same shapefile, and ...
2
votes
2answers
30 views

Selection of lines that lays mostly in defined zone (majority overlap)

I have lines of surface runoff and I need to select the ones that are lying mostly in internal buffer of polygon. I'm trying to make some script in python, but it's very important to make the script ...
0
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1answer
29 views

Erdas python scripting help

I want to write scripts for Erdas in Python. I downloaded some Python examples here but I could not make much. Where can I get the full Help material for Erdas python scripting?
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0answers
33 views

Batch Convert shape files into aoi's in erdas

How to Convert Shape files in batch mode to aoi's in erdas through python script?
7
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2answers
179 views

Conflict between ArcPy and GDAL/OGR?

TL;DR I can't get an installation free version of GDAL/OGR to work from within ArcMap 10.0. I get an ImportError: DLL load failed on _mod = imp.load_module('_gdal', fp, pathname, description). ...
0
votes
1answer
88 views

Writing shapefile with projection defined crashes fiona

I've just started trying to use Fiona to write out shapefiles. I found the example code below, which seems to work fine from shapely.geometry import mapping, Polygon import fiona # Here's an example ...
2
votes
1answer
83 views

Does not show shortest path in networkx (in QGIS)

I used the following commands (in qgis console) to get the shortest path with astar algorithm. But the result shows 'NetworkXNoPath' every time. Why was that? Please help me to find a solution to this ...
6
votes
1answer
74 views

Competing approaches to line & polygon simplification

There seems to be a few theoretical options around at the moment for geometric simplification. Douglas–Peucker seems the most established, followed by Visvalingam's approach (used by d3.js). Now ...
3
votes
1answer
226 views

How come “Zoom to Polygon” always puts me in the middle of Nebraska?

This is an issue related to this question I'd asked a few days ago. I've got that code working, to an extent. Every time, though, that I double click on one of the Polygons in the attribute table that ...
1
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1answer
48 views

Communicate synchronously & continuously (coords, etc) from terminal to application-based mapping software such that updates are displayed live on map

I run a lot of spatial queries. Hundreds of thousands a week. While these things are running, it would be nice if I could see what (where, actually) my scripts are working with. Distance calculations, ...
7
votes
1answer
871 views

Inserting newlines in Rectangle Text elements via ArcPy causes overlap?

I ran across an issue the other day when I tried to use ArcPython's mapping module to edit rectangle text elements with newlines (\n) in an ArcMap document. Here's what the output looked like: ...
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0answers
20 views

How to sort a column in attribute table programmatically

Is there any way to sort ( alphabetically ) a column in the attribute table programmatically (without clicking on the column header) in QGIS ?
0
votes
1answer
27 views

40k+ points from Shapefile, clustering them and populating on Google Maps/Webapp

I just started a new Python/Django webapp job related to GIS (and i'm totally new to GIS). Here is my task and what i have found so far, and i am stuck as to finding out what's the best way or the ...
3
votes
1answer
174 views

Load and display a layer using PYQGIS

I'm having a go at using pyqgis from within the QGIS python console to load a layer from SQL Server and display it. I feel like I'm part way there but I'm having a real issue getting the layer to ...
2
votes
1answer
47 views

data source for worldwide cross-sections of topographic and bathymetric for woodworking art project?

i am a decent r programmer and statistician, i am able to work with data sets pretty well. i am less familiar with GIS tools, but if given a shapefile i can certainly plot political borders and ...
3
votes
1answer
75 views

PostGIS: Insert a Point using Python

What is the right way to insert a Point to a PostGIS database using Python?
5
votes
3answers
596 views

How to convert geoJSON to python objects?

New to the site, and to geoJSON, and to python. My goal is to read in a file with geoJSON data, and use it to generate shapes to be used in an application that is using python scripting. Python has ...
0
votes
3answers
314 views

Run function if item in QComboBox is selected

I got another issue writing a plugin to convert three shape files into an .obs input file. I created a UI (Qt) with a QComboBox to select a layer (that works fine). As soon as one of the layers in the ...
0
votes
1answer
139 views

Polygon Neighbors Analysis script (ArcPy 10.1) producing erroneous results?

I'm struggling with a python script that is supposed to calculate a field for a polygon feature class. The calculation is of the average of a field value (P_TOT_DEV) for each of a given polygon's ...
0
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0answers
38 views

Python + GME (Spatial Ecology) + Subprocess.call

I'm trying to run the following code to use GME commands in Python. import arcpy,os,subprocess from arcpy import env env.workspace=r"D:\Users\myname\Desktop\aviso" count=0 for raster in (f for f in ...
0
votes
1answer
40 views

Cannot put a layer name as the same as the raster name just created by Python script

I have a question regarding Python script for making a Heat Map Tool. I am making a Heat Map Tool where users can set the map extent, the tool will read the current scale of the map, then make a ...
1
vote
1answer
40 views

Controlling Python Version from ArcGIS?

I am writing a VB.net console application that calls ArcGIS Desktop 10.1 ArcToolbox geoprocessing tools from my code. Some of these tools use Python syntax and I am encountering a problem that I ...
1
vote
1answer
21 views

Couldn't load SIP module (QGIS doesn't load Python)

I recently installed QGIS 2.4, but Python does not load. I am running on a Windows 64 bit machine. I receive the error message "Couldn't load SIP module Python support will be disabled". Traceback ...
1
vote
1answer
35 views

What is the inverse of QgsGeometry.asGeometryCollection() in qgis python?

What is the inverse operation of QgsGeometry.asGeometryCollection() as documented here: http://qgis.org/api/classQgsGeometry.html#a7cb1cbf8cfa441456067a66ad3a25a94 I'd like to do something like: ...
1
vote
1answer
85 views

How does one modify selected geometry with a function in qgis python console?

My example use-case is that I want to redistribute vertices along lines as in: Redistribute linestring vertices to specified distance How to create points in a specified distance along the line in ...
3
votes
1answer
216 views

How to clip a Oracle query layer directly in a Python script?

I have a query layer directly running from ORACLE database in a MXD. I want to clip this layer with a layer being created in another MXD in a Python based tool. My question is to do this clip ...
0
votes
0answers
27 views

Is it possible to rotate the geographic projection in QGIS?

I'm trying to create a Qgis plugin that can rotate a raster layer in the canvas so that the north is pointing at another direction. Unlike the thread below, I'm open to defining a custom projection. ...
3
votes
1answer
182 views

Python Postgres Multiprocessing speed increase

I'm trying to speed up my PostGIS queries using multiprocessing. My current setup is using python and psycopg2 such as below. Although this has given a speed increase, it still seems like there are ...
0
votes
2answers
104 views

How to copy attribute values of fields in selected features of one layer to another Qgis programmatically?

I am trying to get the values of attributes of the selected features of a layer field by field and copy to another layer that I created in qgis with pyqgis. Is here a example for this. Every example ...
1
vote
1answer
135 views

PGRouting Layer plugin error in QGIS 2.2

I am trying to do some basic computations using the PGRouting plugin for QGIS, but I am getting this error all time: An error has occured while executing Python code: Traceback (most recent call ...
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votes
0answers
30 views

Update fields in feature class [duplicate]

I am working on ArcGIS 10.2.1. I have a feature class containing more than 4000 records and a table having approximately 1000 records. Both feature class and table have some common fields however, ...
0
votes
1answer
49 views

Updating a feature class

I am working on ArcGIS 10.2.1. I have a feature class containing more than 4000 records and a table having approximately 1000 records. Both feature class and table have some common fields however, ...
0
votes
1answer
18 views

Zoom option error on gdal_tiler.py

I'm using the tiler-tools library from: https://code.google.com/p/tilers-tools/wiki/QuickStart And specifically this command: ./gdal_tiler.py --zoom=9-15 my_map.vrt To generate tiles. When I use ...
2
votes
2answers
297 views

How to use gdal module in python

I am trying to import gdal modules from osgeo installed in my win64x machine but I get the following error: Traceback (most recent call last): File "", line 1, in from osgeo import ogr ...