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

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10
votes
2answers
327 views

Determine minimum number of polygons from shapefile to cover an area of interest

I have a large number shapefiles representing areas of interest for an analysis that will be conducted using various sources of satellite imagery (IKONOS, RapidEye, etc.). Unfortunately, the imagery ...
9
votes
2answers
519 views

Best design for Open Source Python / PostGIS prototype

I am writing a data intensive web application that is delivered through apache. My question is about how to best arrange processing given that there are multiple options. I have at my disposal ...
3
votes
2answers
2k views

From text data create a FeatureClass with table with python

I'm searching how the output of one program (text file with some writings, but also with data as numbers, dates, times, coordinates, all separated with commas) can be transformed to a Feature Dataset. ...
1
vote
3answers
1k 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 ...
2
votes
1answer
295 views

Count the number of symbols in a 'new symbology' renderer from pyqgis

Background : I create a lot of symbology using 'saturation' ramps - for want of a better term, e.g. where the hue and value of each symbol stays the same, but the saturation changes. I couldn't figure ...
0
votes
1answer
4k views

function, return, 'instancemethod' object has no attribute '__getitem__'

I'm still trying to write a python plugin to create an input file for an urban climate model out of three shape files. Now I stumbeled into another problem, that I think is an easy one, but I just ...
2
votes
2answers
666 views

How to single out country data from a world data map?

Say that i have two "data sources"; A global map of average wind speeds, A shape file (or similar information) of all country borders in the world. How do i combine these two sources and extract ...
0
votes
1answer
504 views

Remove Illegal Characters in Model Builder [duplicate]

Possible Duplicate: Arcpy remove invalid character I've created a model that iterates through a shape file and pulls out unique values in a field. These unique values are then used to ...
8
votes
1answer
2k views

concurrent use of in_memory workspace in arcpy

i am using a python script that's eliminating small polygons from a feature class. this script creates temporary feature classes with fixed (hardcoded) names in the "in_memory" workspace. example: ...
9
votes
2answers
7k views

Using the python shape library: pyshp - how to convert .csv file to .shp

I am trying to understand how I can use the csv module in python to open a csv file in the same folder as the python script, and then create a shapefile using the shapefile module pyshp. The csv file ...
6
votes
1answer
3k views

Passing a variable from a script to ModelBuilder

I have a model that passes a variable to a python script. The script uses that variable to query some directories and return a list of paths. What I want to know is: how can I then use each of those ...
0
votes
1answer
1k views

arcpy - how to run geoprocessing python script on SDE

I was testing my script on a .gdb on my local drive and I got it to work. The actual geodatabase I would like to run the script on is an SDE. I tried changing my filepath from the .gdb to the .sde and ...
3
votes
3answers
1k views

ArcGIS Field Calculator Python numbering rows of fishnet

I have a grid of 100*100 cells. I want to add to each cell a number representing the row it is in (like in excel). I added a field and want try to solve that with field calculator: The code is ...
2
votes
1answer
527 views

Can you script publishing a GP service?

I have a geoprocessing service in ArcGIS for Server 10.1. I would like to share this service with a number of external organisations that also have ArcGIS Server 10.1. i.e I dont want them hitting ...
21
votes
3answers
13k views

What is the proper syntax and usage for ArcGIS “in_memory” workspace?

I am unclear how best to use the in_memory workspace in ArcGIS. The best resource I have found on the subject is from ESRI on Using in-memory workspace. Unfortunately, the help section is not very ...
4
votes
1answer
1k views

Get extents of vector shape features in python

i am just wondering if it is possible to iterate through vector features and return the extent per feature without clipping the vector shape? The code looks like this and comes from the ...
3
votes
1answer
151 views

Listing installed QGIS plugins via PyQGIS

Can you please tell me how I can programmatically (or from the console) access the loaded plugin list? I tried: QgsProviderRegistry.pluginList() but got: TypeError: ...
3
votes
1answer
538 views

How to programmatically determine whether a spatial reference factory code is valid?

I am using the following code segment to create a spatial reference. spatialReferance = arcpy.SpatialReference() spatialReferance.factoryCode = spatialReferanceFactoryCode ...
1
vote
1answer
288 views

How to add a custom SymbolLayerV2 to a Vectorlayer in QGIS

I'm trying to add a symbolLayer with a line-decoration (line-arrow) to a vectorlayer of linestrings. what i am trying at the moment is to create a new layer and set it's QgsLineSymbol with a list of ...
3
votes
1answer
904 views

Creating Selection MapTool in PyQgis Custom Application

I'm developing a custom GIS application using PyQgis API. How can I let the user select features on the map using Maptools? I would like to replicate the select feature there in Qgis to make the ...
2
votes
1answer
565 views

Multiprocessing error in QGIS with Python on Windows?

I have this error when I try to use Manager() from python multiprocessing library. (Just start QGIS open Python console and execute the two following lines) >>> import multiprocessing ...
1
vote
1answer
670 views

Why do glob.glob and gdal_translate not work for me?

I have a little problem with my python script. I wrote it to convert MODIS data from .hdf into .tif. It will convert all files in a folder using a loop. I do not know which command I must enter to ...
0
votes
2answers
1k views

Unable to delete .lock files within geodatabase using Python

I am having problems with lock files while deleting and copying geodatabases for backup purposes. print "Now backing up your Geodatabase" distutils.dir_util.remove_tree ...
4
votes
1answer
2k views

Python script for constructing a WHERE clause from user input

I'm trying to construct a where clause from user input that will eventually be passed through as a SQL statement in the select tool or the select by attributes tool. I've started a script thats been ...
2
votes
1answer
346 views

How to get all attributes from a non geometry PostGIS layer with Python in QGIS?

I want to extract all attributes from a non geomety layer in QGIS with Python, but there is only the function uniqueValues(fieldIndex) More specific: I have a postgresql table which is loaded into ...
1
vote
1answer
268 views

Is there any python function to rotate map layers?

Is there any python function allowing a user to rotate map layers in the map canvas. If so, could you please point this out for me? I want to rotate a map layer, using a factor of rotation in ...
4
votes
2answers
1k views

Arcpy remove invalid character

I've built a model that takes the name of the Excel worksheet containing xy data, and uses that name as the name of the output shapefile. ( Worksheet "massachusetts_sightings" in an xlsx becomes ...
4
votes
2answers
2k views

How to Open a File Geodatabase with ogr? [duplicate]

Possible Duplicate: How to access feature classes in File Geodatabases with python and gdal? I have installed: python-2.7.msi GDAL-1.9.1.win32-py2.7.exe import ogr driver = ...
1
vote
1answer
273 views

arcgis python window VS pywin32

I have problems while using the ZonalHistogram function in Python. It seems to give strange results, while, with the same code run in arcgis' python window everything works fine. I am trying to study ...
6
votes
3answers
906 views

How can I use py2exe with the OSGeo4W Python installation?

I have a default Python installation in c:\Python27. I have also installed Python through the OSGeo4W installer, which has created a "sandboxed" Python installation with all the geospatial bindings I ...
7
votes
3answers
7k views

How to create lines from points pair coordinates with arcpy?

I've got some points pair coordinates (start and end points) which I have to transform into lines. Until now, I used an append of both the coordinates in a pippo.Point(), a pippo.CalculateGeometry() ...
8
votes
3answers
3k views

How do I get the path of a project, or layer file in PyQGIS?

I am generating new raster files from vector layers on a project. I would like to save them in the same directory as the project or layer files. How do I find this path using PyQGIS?
54
votes
10answers
5k views

Alternatives to using Arcpy

I seem to use ESRI's Arcpy site package for virtually all of my python geoprocessing. To ESRI's credit, these are an incredible suite of tools that can help accomplish a great deal. However, I would ...
1
vote
1answer
247 views

QGIS python plugin, segmentation fault, what can I do?

I'm trying to write a python plugin to create an input file for an urban climate model out of three shape files. Unfortunatelly QGIS closes when I try to load the plugin. When I start QGIS from the ...
0
votes
1answer
116 views

How can i use ihookhelper interface in python?

I use ArcObject in python to develope a tool. I import comtypes in python to access the arcmap layers in python and use ifeaturelayer interface. I have to set featurelayer to ...
16
votes
5answers
2k views

How are people using Python data structures and classes in ArcPy?

This question may expose my ignorance on programming but I'm curious about how people are using different python data structures within ArcPy. This page lists the data structures in Python. I ...
2
votes
2answers
2k views

How to create a map with states by attribute value?

I'm using Qgis, but I am quite familiar with R and python. So I could use any of these. I want a map of mexico but want to color the stats according to a certain variable. It goes from 0 to 100. So ...
5
votes
1answer
747 views

Create point between two points with given distance or length

What I have: Coordinates of Point A and Point C and therefore vector and azimuth from A to C What I want: Coordinates of Point B (between A and C) with a distance from A to B of 35.2 meters. ...
5
votes
2answers
260 views

Using newly created features in the next part of a python script

Good Afternoon I am trying to write a python script which buffers a large number of features from a geodatabase (but not all) and then dissolves the newly created buffer shapefiles together. ...
5
votes
1answer
2k views

How to create mask bands in GDAL and Python?

I have small program in Python that uses gdal and numpy to perform a logarithmic scale of some data into the RGB 0-255 range. Now this input data has a nodata value set to mask the valid values, and ...
1
vote
0answers
427 views

Why won't this PostGIS query display in QGIS

I am having trouble rendering the following PostGIS query in qgis1.803. SELECT s.musym, st_intersection(s.the_geom,f.the_geom) as geo, nextval('"soilsplittersequence"'::regclass) as k From ...
3
votes
1answer
2k views

how to get the projection from a vectorlayer in qgis?

Hi I am trying to set the projection on a raster to match that of a vector point layer. Thus I need to findout what is the projection of a give layer, to use it in the GDAL.Dataset.SetProjection() so ...
0
votes
0answers
119 views

How to create a pop up attribute table for each crash located on a roadway segment in arcmap

I am trying to create a simple user interface that displays information for each crash located on the routes. I also need to display a graph along with that. I am a beginner in Python with no prior ...
0
votes
1answer
1k views

Error : keyword can't be an expression

I am getting "keyword can't be an expression" error while running the following code: >>> import arcpy >>> arcpy.MakeFeatureLayer_management("Point","P1","Layer" = 'WM-VALVE-ID') ...
2
votes
1answer
411 views

Python script for Data Driven Pages to run a series of DDP at once?

I have a several different polygon shapefiles that I am using to create individual maps for each polygon within the shapefile. The layout is the same for each map, the only thing that changes is the ...
1
vote
2answers
668 views

ogr: how to use epsg database for RD New projection?

I'm trying to assign this EPSG projection to my newly created shapefiles using ogr. The OGR Projections Tutorial says: ...any geographic coordinate system in the EPSG database can be set by it's ...
5
votes
1answer
1k views

How to Create a raster layer from a numpy array using pyqgis?

I am working on a plugin for Qgis to calculate spatial Kernel density maps. I have all the calculations working, all I am missing is a way to turn a Numpy Array, with density values into a multiband ...
10
votes
2answers
335 views

Count raster value in a bounding box (spatial extent)

I have simple question: given a bounding box, how can I count the number of specific values (say, I am interested in the number of value == 1 ) in a raster in 1) arcpy, or 2) raster package in R?
6
votes
1answer
2k views

Retrieve path and file name of current qgis project in python

Is there a way to get the path and the file name of the current project from a python script? I'm currently trying to develop a python plugin for qgis and I need to create a file with a similar name ...
3
votes
3answers
261 views

How to compare a set of images with a shapefile?

I have around 150 images (rasters), each one is just a map of certain "classes", e.g. pixel value 1=forest. I also have a shapefile that consists of roughly the same area as the 150 images constitute ...