Questions tagged [python]

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

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138
votes
5answers
27k views

Accessing ArcObjects from Python?

I would like to be able to script some things that are not exposed via arcgisscripting or ArcPy. How do I access ArcObjects from Python?
21
votes
3answers
16k views

Problem with import qgis.core when writing a stand-alone PyQGIS script

I am trying to write a stand alone python script in windows 7 that uses qgis.core and various other qgis libraries. I have found an old question on this subject here: Writing standalone Python ...
100
votes
13answers
155k views

Installing GDAL with Python on windows?

Can anyone explain how to install GDAL/OGR with Python on Windows? I have Windows Vista and I have tried following the information on the website and it does not seem to bind the exe files for me. ...
46
votes
1answer
30k views

Getting pixel value of GDAL raster under OGR point without NumPy?

I am working on a computational model of the abundance of wild pollinators across a landscape. The model itself is complete, and I am now struggling with a post-processing step. I have my GDAL ...
77
votes
8answers
145k views

Converting projected coordinates to lat/lon using Python

This site returns Point: X: -11705274.6374 Y: 4826473.6922 when you search with the first key value of 000090, as an example. I assume that this is a spatial reference. I am looking for instructions, ...
4
votes
1answer
4k views

Masking NetCDF time series data from shapefile using Python

I have a 3-D time-series precipitation data (187 x 1800 x 3600), stored in a NetCDF file. I need to obtain the precipitation data for a shapefile. import matplotlib.pyplot as plt from netCDF4 import ...
46
votes
5answers
57k views

How to call gdal_translate from Python code?

Is it possible to use some gdal API to call gdal_translate from Python code? I do not mean simply executing the gdal_translate.exe from the file system, but rather call it somehow in code so I do not ...
35
votes
8answers
46k views

How to set all pixels with value <= 0 to “nodata” in DEM raster?

I have a DEM raster with pixel values between about 3000 and -0.0003. I need to set all pixel with a value of 0 and smaler (<=0) to "nodata" (for later raster calculations and to reduce the ...
36
votes
5answers
50k views

Writing numpy array to raster file

I'm new to GIS. I have some code that converts infrared images of Mars into thermal inertia maps, which are then stored as 2D numpy arrays. I've been saving these maps as hdf5 files but I'd really ...
14
votes
3answers
11k views

How to add support for FileGDB (Esri file gdb API) driver in fiona?

There has been a tons of questions on that but none of them solved my problem. I have a machine with: Windows 7 x64 Python 3.4.3 x64 gdal installed: gdalinfo --version --> GDAL 1.11.4, released ...
35
votes
5answers
57k views

How to write Shapely geometries to shapefiles?

Can someone demonstrate a simple way to write geometry data-structures from shapely into shapefiles? I am particularly interested in polygons with holes and linestrings. It would also be beneficial to ...
10
votes
2answers
4k views

Guidelines for using ArcObjects from Python

By far, Accessing ArcObjects from Python? is my most read and referenced Q&A on GIS Stack Exchange. In spite of that success, it's probably one of my weakest areas when it comes to actual use. A ...
10
votes
4answers
7k views

Iterating over layers and export them as PNG images with PyQGIS in a standalone script?

I would like to export specific layers as a png from a QGIS .qgs map. From the table of contents the script would first export the "boundary, climits, and Div1_Irrig_1956_0" layers as one png. The ...
32
votes
4answers
54k views

Fully load raster into a numpy array?

I have been trying to check my filters on DEM raster for pattern recognition and it is always resulting in missing last rows and columns(like..20). I have tried with PIL library, image load. Then with ...
22
votes
4answers
25k views

Using ogr2ogr to convert GML to shapefile in Python?

I am trying to convert a GML to an ESRI shapefile using ogr2ogr utility in a python script. I have successfully installed the GDAL/OGR package via osgeo but I am now struggling to find/understand ...
11
votes
2answers
6k views

Programmatically load composer from template and generate atlas using PyQGIS

I am trying to build a plugin to load a print composer from file, generate an atlas and export to image. So far I have been successful in loading the template and exporting it to image. I have been ...
17
votes
3answers
14k views

Dissolving polygons based on attributes with Python (shapely, fiona)?

I have been trying to create a function that does basically the same thing that the QGIS "dissolve" function. I thought it would be super easy but well apparently not. So from what I have gathered ...
15
votes
2answers
18k views

How to change the value of an attribute using QgsFeature in PyQGIS?

I would like to update one attribute of a feature. However, I don't know to update it using the feature object. I have to use data provider to update it. layers = QgsMapLayerRegistry.instance()....
6
votes
3answers
4k views

Python, comtypes and ArcObjects: Error creating AppROT object

I am experimenting with comtypes and ArcObjects under Python 2.6.5 and ArcGIS 10 SP1. I'm using the pure Python method to wrap the ArcObjects OLBs described in this answer, but getting an error in the ...
4
votes
2answers
12k views

Intersect Shapefiles using Shapely

What I'd like to try and do is intersect some point buffers with census tracts, maintain their ID's and the tracts attributes. I found a sample from http://www.macwright.org/2012/10/31/gis-with-...
11
votes
2answers
4k views

Add layer to a QGIS group using Python

I am trying to add new layers into a specific group which I can get to work if I know the index, but how can I get Python to find the index of a group so it can load the new layer into the group ...
7
votes
1answer
714 views

Buffering point with different distance toward N, E, S, W using ArcGIS for Desktop?

I want to create buffer polygon(with curved edges) from points like this using ArcGIS for Desktop. distance toward North from a point 5, toward South 1.5, toward west 1, toward East 2. all this ...
37
votes
7answers
23k views

Nearest neighbor between point layer and line layer? [closed]

I've asked this question several times on stackoverflow and irc between #qgis and #postgis and I also tried to code it or implement it my self in postgis with no real answer. Using programming (most ...
18
votes
3answers
26k views

gdal ImportError in python on Windows

Trying to import gdal for Python 2.7.3 on Windows XP: >>> import gdal Traceback (most recent call last): File "<stdin>", line 1, in <module> File "C:\Python27\lib\site-...
3
votes
3answers
4k views

Couldn't load SIP Module

After reinstalling QGIS, the desktop program runs but generates the python error "Couldn't load SIP Module Pythin support will be disabled" Because of this error, no plug-ins will load. I found a ...
49
votes
17answers
36k views

Learning Python programming with generic GIS goals in mind?

In your opinion, what is the best book/site to learn Python with GIS goals in mind? By "best", I mean: not very long (book) easy to understand (book/site) good practical examples (book/site) For ...
38
votes
4answers
28k views

Simple thematic mapping of shapefile using Python?

I wish to visualize geographical data in Python, without using ArcGIS/ArcPy, and make a map. On the internet I found how to make a thematic map using Python: Here is some code that I tried: ...
33
votes
6answers
42k 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 ...
29
votes
1answer
4k views

Creating sector lights in QGIS?

I'm using QGIS 2.18. I need to create sector lights for navigational purposes on a map. I have the light sector data as fields giving becon_id, start degree, end degree and color in a shapefile with ...
27
votes
3answers
34k views

Clipping raster with vector layer using GDAL

I have installed GDAL using the Osgeo installer. How can I clip a raster layer with a vector layer programmatically? Is there any GDAL API available which can help me with this? I am using Python.
8
votes
1answer
5k views

How to evaluate raster calculator expressions from the console?

How can I execute from the console an expression that should be used with the raster calculator? I'm searching for something like this: qgis.someRasterCalcClass.evaluate("boh@1 + boh@2", "outputfile....
8
votes
2answers
2k views

Plugins crashing with “No module named qgsprojectionselectionwidget” in Windows?

My Python QGIS plugin works on Ubuntu (at least for me, and all fatal bugs reported so far are solved), but when I run it on QGIS installed from the official 2.10.1 64-bit installer for Windows (on ...
4
votes
1answer
2k views

How to render area that crosses 180°?

The problem is that the Chukotka Peninsula is located in the Western Hemisphere. So it is on the left side of Natural Earth Datasets. It needs to be moved to the right. I tried to use following srs(...
20
votes
1answer
33k views

Getting coordinate system name from SpatialReference using GDAL/Python

In Python, using GDAL, I've extracted a raster's projection as a WKT string as follows: wkt = dataset.GetProjection() # wkt is 'PROJCS["GDA_1994_Transverse_Mercator",GEOGCS["GDA_1994",DATUM["GDA_1994"...
31
votes
10answers
16k views

Seeking Python tools/modules/add-ins for GIS?

With ArcGIS 10, Python has become the de-facto scripting language for ESRI. While leading Open source software like QGIS, GeoServer, PostGIS all supports Python. Thus it became important to know/learn ...
84
votes
24answers
109k views

Python GDAL package missing header file when installing via pip

I asked this question on Stack Overflow before I realised this site existed. As this site it more appropriate, I'll ask it here too. I'm trying to install gdal from pip pip install gdal inside a ...
33
votes
3answers
28k views

Transforming Shapely Polygon and MultiPolygon objects

Is there an easy way of transforming Shapely objects (namely, Polygons and MultiPolygons) from one projection to another without having to dig around and extract coordinates by hand? In fact, I don'...
24
votes
5answers
27k views

Adding attribute field to existing Shapefile via Python without ArcGIS

I have a Python script that adds an attribute field to a Shapefile if doesn't exist. This is easy to do with ArcGIS (graphically or via Python), but I'm looking for something that doesn't depend on ...
36
votes
10answers
43k views

Generate points that lie inside polygon

I have polygon feature and want to be able to generate points inside it. I need this for one classification task. Generating random points until one is inside the polygon wouldn't work because it's ...
17
votes
2answers
15k views

Using Rasterio or GDAL to stack multiple bands without using subprocess commands

Does anyone have a eloquent way of stacking multiple .tif files into a multiple band stack using Rasterio and/or GDAL? I am looking for a way to avoid using a subprocess command like gdal_merge.py ...
8
votes
1answer
2k views

What is the purpose of some functions and files in QGIS Python plugins?

I'm just trying to understand the architecture of a QGIS Plugin created with the QGIS Plugin Builder, as well as the workflow and the linkage among generated files. If possible, I'd prefer a diagram. ...
12
votes
1answer
16k views

Georeferencing raster using GDAL and Python?

I want to georeference a raster using python and GDAL. My current approach is to call gdal_translate and gdalwarp using os.system and an ugly list of ground control points. I'd really like a way to do ...
10
votes
2answers
5k views

How to automatically reload raster layers if source is changed in QGIS?

How to automatically reloaded raster layer if source is changed? (The path is the same but inside source file are changes) I use: qgis.utils.iface.mapCanvas().refresh() but layer not refresh. # #...
6
votes
2answers
3k views

ArcObjects + comtypes at 10.1 and newer

Has anyone played around with using ArcObjects in Python at version 10.1? I am having all sorts of problems, such as TypeErrors when wrapping the ESRI OLB modules and AttributeErrors when attempting ...
10
votes
6answers
13k views

Starting and stopping ArcGIS Server map services using Python?

Is it possible to programmatically stop and start ArcGIS Server map services using Python?
6
votes
3answers
7k views

Reclassifying rasters using GDAL and Python?

Using @SS_Rebelious very useful answer, I am trying to reclassify rasters using GDAL and Python. I have a grayscale raster (with values ranging from 0 to 255) and I want to reclassify it to a binary ...
2
votes
1answer
4k views

Setting QGIS Python version?

I have brewed python 2.7.3 onto my Mac (Lion), and installed shapely via pip install shapely. The Polygonizer plugin, however, does not find the shapely library. I see when QGIS loads a Python console,...
35
votes
4answers
41k views

Python Script examples for geoprocessing shapefiles without using arcpy

I would like to use a Python script that is not based on arcpy to do things like query a shapefile by attributes, create new layer from selection, and calculate areas of a polygon and convert ...
36
votes
3answers
26k 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 ...
14
votes
2answers
17k views

Extract raster values within shapefile with pygeoprocessing or gdal

I would like to know how to get all the raster values within a polygon using gdal or pygeoprocessing, without reading the entire grid as an array. pygeoprocessing and gdal can do zonal statistics but ...

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