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

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4
votes
2answers
1k views

Select by attribute expression invalid in python

I'm not sure how my expression is failing. Any ideas? inPoints = "points.shp" i = 0 arcpy.MakeFeatureLayer_management(inPoints, "pts") arcpy.SelectLayerByAttribute_management("pts", "NEW_SELECTION", ...
1
vote
1answer
168 views

Running a QC check for gaps between vertices on a polyline

I'm checking polylines to make sure power pylons were correctly extracted from imagery. Is there a way to find all of the gaps or missed pylons in the database? Currently, I'm manually making a ...
6
votes
3answers
709 views

How to Run Viewshed on one feature at time in shapefile?

I have over 100 features in a shapefile and I want to create individual viewsheds for each and then run processes on each of those resulting viewsheds in ArcGIS using Python. Is it possible to write ...
0
votes
1answer
227 views

Qgis - taudem plugin - python script not found

I installed the sextante toolbox on qgis. my os is fedora. grass works fine but i've got problems with taudem. it seems like some python files are missing. for instance when i try to run the ...
0
votes
1answer
246 views

How can i select many rows from a table?

I want to create an action that select many rows from PostGIS table to show many lines in QGIS. How can i select many rows from table with python to add these rows in a layer? Thank you
0
votes
1answer
481 views

Local variance image in python using gdal and a running window approach

I want a local variance image with a 3x3 of a geospatial raster image using python. My approach so far was to read in the raster band as an array, then using matrix notation to run a moving window and ...
0
votes
1answer
466 views

openlayers python proxy.cgi script is not taking parameters

I have setup the python proxy.cgi in cgi-bin folder in my server. [myserver]/cgi-bin/proxy.cgi returns the openlayers website [myserver]/cgi-bin/proxy.cgi?url=www.openlayers.org returns list index ...
2
votes
1answer
274 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 ...
3
votes
3answers
13k views

Use Python to parse string [closed]

OK, I know that this is Python 101, but I can't seem to figure it out. I have a function setup that will return a string, specifically an azimuth in DMS. I need to take the return values and pull ...
5
votes
1answer
8k views

Python GDAL: Save array as raster with projection from other file

I have an array of data, and for each datapoint I know the latitude and longitude. I'd like to save it as a GTiff with the same projection as other rasters I have. This is what I've tried so far, but ...
2
votes
0answers
223 views

How to programmatically change an SVG symbol in the Vector Layer?

I'm trying to change the symbol used in a layer via Python. I've been able to tunnel through a vector layer to the symbol layer, but I don't know how to change the symbol it's using. I'd like to ...
7
votes
2answers
961 views

Autoincrement field when New Feature added

I know that this is probably a very basic programming but I am brand new to Python. I have a layer in a geodatabase that I need a unique ID field (for joining). I can't use the ObjectID because that ...
2
votes
1answer
446 views

Writing python plugin: How terminate plugin from script without closing QGIS?

I'm writing a QGIS conversion plugin in python to be able to create Obstacle-files for a model from shapefiles. What I want to do now is just to close the plugin cleanly. This means, to close the ...
1
vote
1answer
72 views

How to keep specified separation distance between features in printout from ArcMap?

Does anyone have a solution to select features using attribute values and print only the selection keeping a specified separation distance between the features in the printout in ArcMap.
3
votes
1answer
1k 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 ...
3
votes
1answer
652 views

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

This might sound like a silly question. 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 ...
9
votes
4answers
5k views

How to convert geometry to WKT using ArcPy?

I would like to be able to convert a single feature (or potentially many features) in an ArcGIS layer into Well Known Text (WKT) format during a geoprocessing operation using Python and ArcPy (no ...
3
votes
0answers
142 views

traversing KML files with ogr python

i'm new to OGR processing and KML format so be gentle: i've got a series of KML files all containing multiple regions partitioning a larger area in each. i also have a series of geocoded points for ...
1
vote
0answers
100 views

Clipping Buffers

I have buffered a line shapefile where many lines are intersecting but not broken at intersections. I am trying to select each record in the buffer file and clip all intersecting polygons in the same ...
3
votes
2answers
829 views

Create point geometry in a feature class with all the attributes prepopulated

So here is the problem. I have a text file with space delimited values. A standard text file with the headings separated by spaces and then on each next line values for these headings (columns) also ...
3
votes
2answers
2k views

Delete feature selection using Python (ArcGIS 10)

I'm having some issues with a Python script for ArcGIS 10. The idea is to delete points from a single shapefile according to the values of two columns ("Tracks" and "Tracks_1"). Therefore, I want to: ...
8
votes
1answer
2k 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 ...
2
votes
2answers
731 views

upload table to ArcGIS Server

We are building a process which will allow users to submit a table of GPS data to update our central repository for all GPS data. Let's say that the target is simply a SQL data table. At first I ...
2
votes
1answer
648 views

Python code: Using Search Cursor to find missing values in attribute table between two layers in one MXD

I need help! I am writing a program that will look through the table of a station layer and then go to the annotation layer and list all the missing values. For Example: The station layer has a field ...
0
votes
2answers
2k views

Using Python to parse an XML containing GML tags

I am trying to write a python script which pulls GML tags out of an XML file and formats them into WKT for inserting into a PostGIS database. I have been successful in doing so for an XML containing a ...
7
votes
3answers
4k views

How to replace non-English characters in attribute tables using Python?

I have a few shapefiles where some of the attributes contain the non-English characters ÅÄÖ. Since some queries doesn't work with these characters (specifically ChangeDetector), I tried to change them ...
6
votes
3answers
2k views

Interacting between Openlayers and Python

I have a openlayers website like this one that gives the user the ability to draw polygons and then creates a GeoJSON file. I want to process this GeoJSON with a python script. The python script ...
0
votes
0answers
99 views

Create Vertex and add empty attributes to it

How can I create a vertex(and then a point feature on the vertex) on a polyline and give it some empty attributes(create fields), move an existing vertex, delete vertex? I am in ArcGIS environment and ...
9
votes
1answer
2k views

Pros and cons of using Ruby/Rails/RGeo or Python/GeoDjango for a web based GIS

We're at the investigation phase of creating a web based GIS. We're assessing options for an ORM to use in all of our backend import/export and processing routines. From my research, GeoDjango appears ...
6
votes
1answer
232 views

Why do ECWs go missing when exporting MXD to PDF with ArcPy?

I'm trying to export some MXD maps to PDF with arcpy (ArcGIS 10.1). Everything works fine and dandy except for ECW images, which don't appear in the PDF. However, when I execute the same code from the ...
1
vote
0answers
80 views

How to identify grid shift file used by osgeo in Python?

I wrote a Python script reprojecting points from a source coordinate reference system (SCRS) to a target one (TCRS) both identified by an EPSG code. I would like my python script to retrieve details ...
3
votes
1answer
442 views

OGR - Weird GeomType -2147483645 on polygon shapefile

I am trying to import a shapefile (multipolygon) in an app with ogr but I got an error about invalid geom type. If I inspect the data with ogr like this: datasource = ogr.Open("c:\\temp\\data.shp") ...
0
votes
1answer
152 views

Join multiple shapes in a workspace based on a common field

I’m completely stucked!!! I’m working with meteorological data (wind) but I have to arrange the data for a program to be able to process it. I have text files, two per day (one with the wind direction ...
1
vote
1answer
202 views

How to query and display layer using ArcGIS Python script tool? [closed]

I have database which contains point shapefiles and raster files for 3 species. My aim is to develop a script tool that should have a search tab to enter the species name. also, a check box to select ...
3
votes
1answer
313 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
vote
1answer
254 views

How can I change SQL query through a layer of an action (python)? [closed]

I have three layers from three diferent database tables. When I click in other layer I want to change (with an action) the query of that three layers. How can I do that? Thank you
8
votes
2answers
756 views

What are mystery green lines in Layout View produced during ArcObjects script execution?

Could any of ArcObjects guru tell me, what are these green lines on my Page Layout and what to do, or not to do, so they do not appear? See image attached. I do used ArcObjects from Python. My script ...
4
votes
3answers
942 views

How to create Where Clause from user input via Python list?

I am trying to perform a query based on values in a Python list. The where clause will then be used in an Update Cursor, so that the rows NOT equal to the values in the list will be deleted. This is ...
1
vote
4answers
1k 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 ...
1
vote
1answer
120 views

How to reopen a plugin-window in QGIS?

I am currently taking my first steps in playing around with programming a plugin in python 2.7 for QGIS 1.8. While my plugin does what it should, I would like to make it more userfriendly. At the ...
2
votes
1answer
168 views

How to change VB syntax to Python in Field Calculator?

I want to calculate a field, this is my working example in VB: "C:\Users\Admin\Desktop\Data\" & !Work! & "\1000_\" & !Data! & ".pdf" I'm slowly changing all my scripts to Python, ...
0
votes
0answers
17 views

Sextante Modeler Error “global name os is not defined” [duplicate]

I want to generate a model whic reclassify radter values. So i added Saga reclassify grid values tool to Modeler and saved the model. When i run the model i got this error both on Ubuntu OSgeolive 6.0 ...
5
votes
1answer
376 views

How to create polygons in ArcMap 10.0 using lat/long data from SQL Server 2008 database?

Forgive me if this is very basic, as I'm new to GIS work (though I've been a programmer for 10 years) and so I'm not really sure how to approach this, but here goes... Can I take a table with ...
11
votes
2answers
5k views

How to get raster corner coordinates using Python GDAL bindings?

Is there a way to get the corner coordinates (in degrees lat/long) from a raster file using gdal's Python bindings? A few searches online have convinced me that there is not, so I have developed a ...
0
votes
1answer
109 views

Error on rendering linestring

I am using Mapnik 2.0.1rc0 on a Windows 7 with python 2.7 32bits inside a GeoDjango App using xml. The datasource come from spatialite 4.0. My tiling script can render polygon and point features ...
0
votes
0answers
331 views

mapnik error - fatal flex scanner internal error--end of buffer missed

I am using Mapnik 2.0.1rc0 on a Windows 7 with python 2.7 32bits inside a GeoDjango App. I often got this error: fatal flex scanner internal error--end of buffer missed that makes python to crash ...
0
votes
1answer
912 views

Where Clause problems when all parts are user input variables

I have written some generic user ipnut code for a toolbox script (ArcGIS 10.0) but because everything is a variable I don't know how to write the SQL whereclause. Please can someone help and suggest ...
2
votes
1answer
770 views

Error 999998 in Arcpy 10.1

I found an RuntimeError: ERROR 999998: Unexpected Error when lunching Arcpy in my ArcGis 10.1 such as this: Runtime error Traceback (most recent call last): File "", line 50, in File ...
3
votes
1answer
383 views

AGS 10.1 geoprocessing service returning the wrong URL

I have an image export geoprocessing service that runs on ArcGIS server 10.1. It works by writing an image out to the scratch folder, and returning the location of that image. Basically just this: ...
1
vote
0answers
725 views

How to transfer the attributes of features based on their spatial relationship?

I'd like to check if a point feature class is placed on a line feature using python in ArcGIS 10.0. I have created a set of point features and placed them directly on a group of line features at ...