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

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How to split shapefile per feature in Python using GDAL?

is it possible to split a shapefile per feature in python? (best would be a solution where i can temporarily save the resulting vector objects to the memory instead to disk). The reason: I want to ...
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1answer
2k views

Is it possible to take automatically a “screenshot” of my selected feature in QGIS using Python?

I am implementing a tool which allows the user to create a profile of a feature (in my case urban parcels). Is it possible to automatically take a screenshot of this feature (displayed in a QGIS ...
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3answers
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How to smooth / “reinterpolate” a raster with GDAL?

Short: I want to change the resolution of a raster and smooth the gray ramp like shown in the images bellow. The preference is to use GDAL, PIL or Numpy. Description: I'm kriging points into rasters ...
11
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1answer
2k views

Copying file geodatabase on ftp site to local disk using Python?

There is a file geodatabase sitting on an ftp site that I would like to download with a Python script. Right now I'm thinking one way to do this is to copy the ftp geodatabase to a geodatabase on my ...
11
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1answer
696 views

Teaching Python to Land Surveyors

Does anyone have any good examples of using Python to automate or simplify common surveying tasks? I'm teaching a Python/ArcPy lab this week for a GIS class. There are a number of surveying ...
11
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1answer
8k views

How to write standalone Python scripts using QGIS?

I've been learning how to use the Python Console in QGIS using references from qgisworkshop.org. I'm familiar with writing standalone scripts in ArcGIS and want to learn how to do the same with QGIS. ...
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3answers
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Exporting features with attachments for use outside ArcGIS?

ArcGIS 10 features the new ability to add attachments to individual features to feature classes stored in a geodatabase. One use of this would be to add multiple pictures to a specific location, fire ...
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4answers
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ArcGIS 10.0 Python SearchCursor file locking

I have a script that gets a value from a shapefile's field to return to the user. It seems that only when the arcpy.SearchCursor is called ArcMap locks the file and it doesn't get removed after the ...
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4answers
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Bilinear interpolation of point data on a raster in Python?

I have a raster that I'd like to do some point interpolations with. Here is where I'm at: from osgeo import gdal from numpy import array # Read raster source = gdal.Open('my_raster.tif') nx, ny = ...
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2answers
195 views

How could I rate roads for scenic drives?

relative GIS newbie here. I've been working on a personal project to rate roads on how nice a ride they'd be on a motorcycle. I wrote a Python program to work through road data in the TIGER dataset (...
11
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1answer
895 views

PyQGIS file lock release

I was wondering what triggers the release of file locks in pyQGIS? I am trying to delete a few data sources (used temporarily) by calling QgsVectorFileWriter.deleteShapeFile, but I have to quit QGIS ...
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1answer
994 views

Link QGIS to Anaconda Python Distribution: Spyder, iPython Notebook, pip, scikit-learn

I have Anaconda as my primary Python distro, and want to route Python related QGIS scripts through it. With Anaconda, I have Spyder, can easily install packages with pip, and can launch a iPython ...
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3answers
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Define Workspace for SDE Connection in Python

How do we define SDE Connection for workspace in Python Scripting?
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4answers
4k views

How to extract the number of vertices in each polygon?

I have ArcGIS Desktop 10.2 and my challenge is how to extract the of number vertices in each polygon for all features like this: I have many parcels in my feature class and I want to extract ...
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3answers
12k views

Converting X,Y coordinates to lat/long using pyproj and Proj.4 returns the wrong coordinates

I'm writing a python script that reads multiple XML files containing x and y coordinates and combines them all into a single csv file. Latitude and Longitude are required fields in the csv, but I am ...
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2answers
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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 create_data_dayer(self,...
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7answers
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How to get X Y coordinates and cell value of each pixel in a raster using Python?

I’m really new to Python and I would like to know whether there is a quick method to get cell values of a raster pixel by pixel and the coordinates (map X Y coordinate of centre of each pixel) using ...
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2answers
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Converting projected geoTiff to WGS84 with GDAL and Python

Apologies if the following question is somewhat stupid, but I am only VERY new to this whole GIS thing. I am trying to convert some projected geoTiff images to WGS84 using gdal in python. I have ...
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7answers
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How to get raster image as array in Python with ArcGIS

When starting to work with Python and ArcGIS 9.3, I assumed there would be a simple way to get a raster image into a Python array so that I can manipulate it before storing it back as another raster ...
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2answers
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Why is this simple arcpy script so painfully slow?

I have a simple arcpy script to update a field in a point shapefile with info from the polygon feature that it is within. It takes 9 minutes to do 100 points in arcpy but a spatial join in arcmap is ...
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2answers
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Creating line of varying distance from origin point using Python in ArcGIS Desktop?

I'm trying to create a line feature from a single point, using a set distance and angle. Using ArcGIS and Python (I hope). I have a point at these coordinates: X = 400460.99, Y = 135836.76 From ...
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2answers
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Finding mid-point of line using ArcPy?

How can the mid-point of a polyline be calculated using the geoprocessing framework, e.g. in a Python script? The polyline.centroid property returns The true centroid if it is within or on the ...
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3answers
8k views

How to round a column in attribute table (ArcMap)

I want to use the Field Calculator in ArcMap to round an existing column to two decimals. Currently I have a column that is 6 decimal places long and would like to simply round it down to 2 decimals. ...
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5answers
796 views

How to improve performance when using ArcGIS cursors in Python with big tables?

I have a pretty big point feature class in a file geodatabase (~4 000 000 records). This is a regular grid of points with a 100m resolution. I need to perform a kind of generalization on this layer. ...
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3answers
823 views

How to download and process raster files in Python?

I am fairly new to python and seek guidance for a question which might sound trivial to many. Is there a way to use 'wget' in a python script to download raster files from a server and process them ...
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8answers
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How to Remove return/newline (\n) character from Field using Python and Field Calculator?

I have a geodatabase table with a field that I'm trying to remove return characters (new line). I found this post (How can I remove (chomp) a newline in Python?) of how to do it, however it is not ...
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2answers
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Creating a multispectral image from scratch

I want to make a multispectral image from cero to do some tests on it. Something really simple like 5 completely uniform bands with salt and pepper noise on them or a square of different values at the ...
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2answers
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Point (of a linestring) within Polygon using ogr and Python

I'm currently working on a project in which I need to build a topological network out of the geometry features I find in shapefiles. So far using Ben Reilly's open source project I've managed to ...
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6answers
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Is there a faster way in python of finding the smallest number in a field?

Using arcgis desktop 10.3.1 I have a script which uses a search cursor to append values to a list and then use min() to find the smallest integer. The variable is then used in a script. The Feature ...
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2answers
3k views

Measuring distance in spherical Mercator vs zoned UTM

I've got points in WGS84 lat/long and I'd like to measure "small" (less than say 5km) distances between them. I can use the haversine formula from http://www.movable-type.co.uk/scripts/latlong.html ...
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4answers
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using shapely: translating between Polygons and MultiPolygons

[EDIT: the solution to this was simply to use OGR to read shapefiles. See geographika's example.] In an ESRI shapefile, there is no distinction between Polygons and MultiPolygons. Furthermore, there ...
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3answers
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Cannot run standalone QGIS script

I've been trying, along with this post, to run a script in OSGeo4w Shell, outside of QGIS. But I get the following error: ImportError: No module named qgis.core I have also read the following ...
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4answers
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Python resource for remote sensing? [closed]

I am looking for a good resource (MOOC, book, etc..) to teach Python for remote sensing applications. I am already familiar with http://www.rsgislib.org/ - are there any other resource out there for ...
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1answer
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Difference between Make Feature Layer (Data Management) and using in_memory workspace?

I was wondering the difference is between Make Feature Layer (Data Management) and using an in_memory workspace? To me, one can use either to do some steps in memory, instead of writing data to a ...
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805 views

Can ArcGIS and OSGeo4W share the same python install?

I don't like unnecessary duplication. Is it possible to install python only once and have both ArcGIS and OSGeo4W using it?
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1answer
195 views

How to save python session in QGIS?

After running a lot of scripts in QGIS' python console, I have more than 10 dictionaries and lists, and I need these for further analysis. Is there a way to save python session, with all these ...
10
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1answer
1k views

Import GRASS and SAGA modules to python script

I'm new at this. I am "building" a python plugin for qgis and I want to import modules from GRASS and SAGA but I don't understand how to do it. The plugin I want to import is Kriging interpolation ...
10
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1answer
942 views

How to address the new “Task-Completed” QgsMessageBar in Python?

I am really amazed what huge steps the QGIS development has taken in the last months. The new iconset, the improved Print composer and many more changes to be seen in QGIS 2.0 are really awesome! ...
10
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1answer
257 views

Birch algorithm does not cluster as expected

I'm using Birch algorithm from scipy-learn Python package for clustering a set of points in one small city in sets of 10. I use following code: no = len(list_of_points)/10 brc = Birch(...
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2answers
338 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?
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1answer
950 views

How to visualize azimuthal data with uncertainties?

I am trying to make a figure showing azimuthal data with a different range of uncertainties at each point. This oldschool figure from a 1991 paper captures the "bowtie plot" idea that I'm aiming for: ...
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2answers
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Error handling with python script in ArcGIS 10

I have a python script that I am using to create a list of all mxd files (with full pathing) in our Projects folder. The script then uses that to iterate through the list and do a ...
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2answers
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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: ...
10
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1answer
528 views

Running ArcGIS 10.0 Under Virtualenv

I am working on a Python package that has a mixture of command line tools and ArcToolbox tools. For Python development it is really useful to use VirtualEnv, especially when working with installers. ...
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1answer
257 views

ArcGIS Pro and ArcGIS Desktop on same machine

I'm just trying out ArcGIS Pro for the first time and I had to change my PYTHONPATH to python34 ArcGIS Pro is now working without crashing every time I open the Analysis tab... However now when I try ...
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1answer
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When iterating over a vector layer with pyqgis, how do I check whether a feature is selected?

While iterating over a vector layer using the following code (summerized from the example in the pyqgis cookbook), is there a way to check whether a feature is selected? provider = vlayer....
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2answers
552 views

Aggregating Polygons To Meet Privacy Requirements

I have a point feature class representing office locations of all employers in a certain industry. The feature class has an attribute for storing the number of employees working at each office. ...
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1answer
490 views

Is there a way to use ArcPy and PyGRASS tools in the same Python script?

I´m trying to write a Python script, that includes different ArcPy / ArcGIS commands and want to combine it with GRASS geoprocessing tools. Unfortunately importing the GRASS libraries doesn´t work. ...
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1answer
959 views

OGR/GDAL threading results in low core utilization

I'm trying to process some raster data using ogr/gdal and I can't seem to get full utilization of all the cores on my machine. When I only run the process on a single core, I get 100% utilization of ...
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1answer
745 views

How to see what lines have changed in an updated Shapefile?

I'm using my county's GIS data to update the roads in OpenStreetMap. I have a copy they published last year and one that was just published, and I'd like to find all the LineStrings that have either ...