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

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4
votes
1answer
233 views

How do I link OGR with spatialite?

Problem & Evidence: I'm trying to create a spatialite file with the code snippet below. However the outDataSource object gets assigned NoneType and all subsequent (unshown) code fails. I'm ...
1
vote
3answers
3k views

Replacing NULL values in geodatabase table?

How do you update NULL values within a geodatabase table using the ArcGIS Field Calculator (service pack 4) without changing other values to NULL? I've tried the suggestions on this previous ...
12
votes
1answer
2k views

How to make a separate Python installation that can call ArcGIS' arcpy?

I see a lot of threads asking how you can create a separate Python installation (e.g. the Anaconda or Python XY distribution) that can use arcpy, while not 'breaking' the original ArcGIS python ...
2
votes
1answer
31 views

Looking to find (or build) a particular Python geoprocessing tool

So here is my situation: There is a large area (a wildlife refuge) of nearly 200,00 acres that we have loads of spatial data for, from habitat management projects from the past several years. My boss ...
5
votes
1answer
65 views

Cutting a circular buffer via Arcpy

I am currently working with compressor stations on centerline routes. These compressor stations have a 3 mile buffer surrounding them. I wish to cut a portion of the circular buffer off. These cut ...
2
votes
1answer
15 views

How to split name in label so only first two words appear?

The labels for my feature SSA_NAME are approximately 5 words long. I would like to shorten the labels to only 2 words. Every time I try a different code I receive either an error message or my layer ...
2
votes
2answers
512 views

Union multiple shapefiles with overlapping shapes

I have several shapefiles that overlap and I would like to union their geometries to get rid of those overlaps. I know how to do this with OGR and Python for single geometries. from osgeo import ogr ...
0
votes
0answers
16 views

Minidump on exit in QGIS (2.8.2- Wien) 64-bit version when using GDAL in plugin

I am working on a plugin for QGIS that is working fine on 32-bit versions but I am having some problems while using it on the 64-bit standalone installation package. I have tried on several machines ...
1
vote
1answer
45 views

If/then python for classifying existing field values to a new field

I'd like to have a tool or quick python script to classify an existing number field to a new text field. For example I have a roads layer that has a type identifier as a coded number and I would like ...
2
votes
2answers
25 views

image segmentation of RGB image by K means clustering in python

I want to segment RGB images for land cover using k means clustering in such a fashion that the different regions of the image are marked by different colors and if possible boundaries are created ...
0
votes
0answers
18 views

How to call the Qt UI of a script?

I'm pretty new in the python world, and I'm working with the python console inside QGIS (Master version on a Debian machine). I have written some scripts, all of them are in the same directory (e.g. ...
0
votes
0answers
29 views

Changing colours in a simple shapefile

I have a very simple map (http://www.nyc.gov/html/dcp/download/bytes/nybb_15b.zip) and I have never before worked with shapefiles in any way. Can someone tell me what I need to do in order to change ...
1
vote
1answer
17 views

Gdal ReadAsArray() different values than gdal band statistics

I am confused about why if I open a band with GDAL I get, for example, band.GetMaximun(): 1000, but if I do ReadAsArray I get myArray.max(): 1200 (the same if I do np.max(myArray)). Does someone knows ...
1
vote
1answer
103 views

Restrict text widget to only integer between 0 and 999 in IntraMaps Roam

I have created a form and added an attribute as a Text widget in the Roam manager. Now I'm trying to restrict the input to be an integer between 0 and 999. I want the field to stay "empty" (or ...
2
votes
1answer
23 views

Error: Algorithm not found (QGIS)

I wrote the following code using QGIS'API. import os from qgis.core import * import qgis.utils prefix_path = os.environ['QGIS_PREFIX_PATH'] QgsApplication.setPrefixPath(prefix_path, True) ...
3
votes
2answers
211 views

How to delete column/field in PyQGIS?

How to remove or delete column fields in a shape file using python?
1
vote
0answers
41 views

Using gdal_merge to merge a large amount of files (in pairs)

I'm new to python and how it can be applied to gis. I have a large amount of MODIS files to go through and I've already extracted, reprojected and converted to GTiff the bands that I need from each ...
2
votes
0answers
12 views

QGIS QgsLayerTreeGroup signal “currentLayerChanged”?

In a pyqgis context, I use the "currentLayerChanged(QgsMapLayer *)" signal of the QgisInterface class to do something when the current layer is changed, but I need now to do the same when I select a ...
1
vote
0answers
11 views

PyQGIS Standalone Crashes python.exe when zooming out too far / Process finished with exit code -1073741819 (0xC0000005)

I have the following PyQGIS Standalone App which is working fine so far. One little problem is that if I zoom out to the MaxExtent(by scrolling the mousewheel) the app crashes python.exe so that the ...
1
vote
0answers
19 views

rasters written with gdal show up with units of meters when they should be degrees

I have some SMOS soil moisture data packaged in a netcdf format distributed by "cp34-bec". I have been able to use GDAL to extract this data as a raster layer, using a projection i think is ...
2
votes
1answer
18 views

Redirect remote shell command output to ArcMap geoprocessing tool display?

I have a Python script that runs a shell command on a remote server (using the Fabric module). When I run the tool in the debugger, I see all the output scrolling, as the command can take hours to ...
0
votes
0answers
16 views

why did my python mysql script stop working, with error on fetchone()?

This code was working a couple weeks ago, then without changing anything, it started throwing an error. Here's the code: #Query climate table sFrom = dateIncrement.strftime("%Y-%m-%d ...
1
vote
1answer
26 views

Python: how to set a different output folder

I want to transform some vectors to rasters in my folder but I have difficulties setting the output folder. The following code only allows me to output to the original database. I hope to output all ...
1
vote
1answer
45 views

“Browse” button returns python error in QGIS

I use the latest version of QGIS (2.8.2) in MAC and have se the default Python version 2.7. Moreover, I have installed all the required python modules and GDAL. It was working before, but now, when I ...
2
votes
1answer
29 views

How to add a message bar to custom canvas?

There is a simple code to add message bar to main window in QGIS: iface.messageBar().pushMessage("Hello","World") My question is how to add bar to my custom canvas canvas = QgsMapCanvas() in ...
2
votes
2answers
62 views

QGIS/Python script to generate random points many times

Good day. Can anybody provide a simple code to be run in the Python Console of QGIS (I am using 1.8 Lisboa) to generate X number of random points (say e.g. 5000) over a certain global shape of ...
0
votes
2answers
428 views

Arcpy SelectLayerByAttribute_management where_clause with LIKE not returning like values

I am selecting 2 intersections from a shape file using info from a File Geodatabase Table. The values are very similar as shown in example at the bottom. I am using a LIKE in the statement but it is ...
1
vote
2answers
69 views

Trouble importing NumPy in GRASS. Architecture

I can't get GRASS to work on my system, and after doing some digging I think it is related to me using 64-bit python. I'm not really sure. I get this message... This module requires the ...
0
votes
0answers
19 views

Extracting pixels latitude into new raster [on hold]

when extracting pixels latitude into new raster the boundary not matched, what shal in do? # -*- coding: utf-8 -*- #!/usr/bin/env python print("Started\n") import gdal import numpy as np ...
2
votes
2answers
438 views

Python problem visualization .tif image

I am trying to read a hyperspectral image in Uint16 .tif format and visualize it. I use GDAL in Python to read the data and everything works perfectly when I use matplotlib to show one band of the ...
1
vote
0answers
18 views

import qgis.core problem with QgsFeature and QgsGeometry ImportError: DLL load failed: The specified procedure could not be found

I've tried several previous answers to similar questions - no luck. I've tried everything, nothing seems to work. This is the error I'm getting Traceback (most recent call last): File ...
1
vote
1answer
152 views

geotiff conversion to coordinate system with gdal

I would like to get the coordinates X Y Z from a geotiff file. I am using the gdal translate for the conversion. Which output format is the more adequate for containing a 3 numpay array X Y Z ?
0
votes
2answers
53 views

Remove first seven characters from field string using Field Calculator

I wrote an expression/codeblock that removes the words "Nearby:" from the field value string if it has it. Codeblock: import string def splitme(s): if s[:7] == "Nearby:": aList = ...
-4
votes
1answer
70 views

Handling ArcPy locks in Python script?

i am writing script which uses different Tools of arcgis and implementing different functionalities .. My script consists in different Functions running in an order. Each function is connected to ...
0
votes
0answers
13 views

Pythonw has stopped working when running arcpy.SubsetFeatures_ga

I'm currently trying to subset a shapefile into training and validation files. When I run the following line of code, python crashes. I'm using ArcGIS 10.1. arcpy.SubsetFeatures_ga(current_shapefile, ...
1
vote
1answer
63 views

How to register “events” for linear referencing in pyqgis?

Is there an easy solution for recording events for a line crossing borders of zones in a polygon layer? I need to implement this in python using QGIS, thus pyqgis. The image attached illustrates what ...
0
votes
1answer
776 views

OSRM API - nearest point fed into routing

I am using the OSRM API to (1) determine the nearest point on a road segment from a give random point with http://server:5000/nearest?loc=_lat_,_lon_ The returned coordinates are used then as an ...
2
votes
1answer
32 views

PyQGIS standalone script does not work. Error “QGraphicsScene::addItem: item has already been added to this scene”

I try to test a PyQGIS standalone script which should just show one Shapefile. Sounds pretty simple but does not work. Here is my script: from PyQt4 import * from PyQt4 import * from PyQt4.QtCore ...
0
votes
1answer
15 views

Semi Automated Classification plugin (QGIS) error when trying to create ROI

When I try to create a new ROI through Semi-Automated Classification plugin (SCP) for QGIS, I keep getting a message saying: "It appears that SciPy is not correctly installed. Please, see this page ...
2
votes
1answer
19 views

problem deleting shapefiles because still in use by arcpy cursor [duplicate]

I have a function outputTblContents which contains def outputTblContents ( path ): rows = arcpy.SearchCursor(path, fields="alpha; beta") for row in rows: print("{0} => ...
0
votes
0answers
22 views

Is it possible to save a dxf in memory

Following on from my question here, when I run the ExportToCAD tool arcpy.ExportCAD_conversion(listOfLayers, formatRelease, location + fileFormat, "Ignore_Filenames_in_Tables", ...
1
vote
1answer
172 views

How to select and zoom in features from a QGIS Python Plugin

I'm very new to Python. I'm trying to find a way to select and zoom to the features from a QGIS layer. I've created a plugin and built a custom form. I have 3 values from the form which I need to ...
0
votes
2answers
45 views
3
votes
1answer
183 views

ArcGis Python Security Concerns

I’m working for a large organization which are using ArcGis Desktop on some (windows) clients. The security requirements for the system is very strict, and a part of that is prohibiting the users the ...
1
vote
1answer
37 views

Setting PYTHONPATH for compiled QGIS version on Linux

I'm trying to set the PYTHONPATH in order to be able to load the qgis classes in a python console (not the QGIS Python one). I followed some resources I've found (PYQGIS Cookbook, and others) but I ...
2
votes
1answer
116 views

smallest, lossless, GDAL ready image format

I would like to know what the smallest file format is I can use with GDAL that fulfills the following criteria: lossless compression (relatively) easy to read/write with GDAL Python bindings least ...
2
votes
2answers
205 views

UpdateCursor on two tables with value from SearchCursor

I try to keep myself busy and learn some python. I have two tables test2.shp (for searchcursor) test.shp (needs to be updated) I want to update test.shp with a UpdateCursor. The column which ...
6
votes
2answers
537 views

Histogram Matching Python

I am trying to do histogram matching using Python to improve the mosaicking process of multiple overlapping rasters. I am basing my code on that found at: ...
0
votes
2answers
146 views

Connecting to Oracle database on a network in python

There is lots of information out there on how to do this, unfortunately, it all looks like Greek to me. I need a connection to a DB so I can add and use tables and featureclasses contained within ...
0
votes
1answer
24 views

Generating elevation 'database' from NED IMG data

I'm starting to work with the NED 1/3 and 1/9 arc-second data. I've been using gdal in Python and QGIS to do some basic conversions of the raw .IMG data from USGS. My goal is to get elevation data of ...