Doc: add a few examples of how to use GDAL algorithms from Python

Author: rouault

doc/source/programs/gdal_cli_from_python.rst

@@ -0,0 +1,128 @@
+.. _gdal_cli_from_python:
+
+================================================================================
+How to use "gdal" CLI algorithms from Python
+================================================================================
+
+Raster commands
+---------------
+
+* Getting information on a raster dataset as JSON
+
+.. code-block:: python
+
+    from osgeo import gdal
+    import json
+
+    gdal.UseExceptions()
+    alg = gdal.GetGlobalAlgorithmRegistry()["raster"]["info"]
+    alg["input"] = "byte.tif"
+    alg.Run()
+    info = json.loads(alg["output-string"])
+    print(info)
+
+
+* Converting a georeferenced netCDF file to cloud-optimized GeoTIFF
+
+.. code-block:: python
+
+    from osgeo import gdal
+    gdal.UseExceptions()
+    alg = gdal.GetGlobalAlgorithmRegistry()["raster"]["convert"]
+    alg["input"] = "in.nc"
+    alg["output"] = "out.tif"
+    alg["output-format"] = "COG"
+    alg["overwrite"] = True  # if the output file may exist
+    alg.Run()
+    alg.Finalize() # ensure output dataset is closed
+
+or
+
+.. code-block:: python
+
+    from osgeo import gdal
+    gdal.UseExceptions()
+    alg = gdal.GetGlobalAlgorithmRegistry()["raster"]["convert"]
+    alg.ParseRunAndFinalize(["--input=in.nc", "--output-format=COG", "--output=out.tif", "--overwrite"])
+
+
+* Reprojecting a GeoTIFF file to a Deflate compressed tiled GeoTIFF file
+
+.. code-block:: python
+
+    from osgeo import gdal
+    gdal.UseExceptions()
+    alg = gdal.GetGlobalAlgorithmRegistry()["raster"]["reproject"]
+    alg["input"] = "in.tif"
+    alg["output"] = "out.tif"
+    alg["dst-crs"] = "EPSG:4326"
+    alg["creation-options"] = ["TILED=YES", "COMPRESS=DEFLATE"]
+    alg["overwrite"] = True  # if the output file may exist
+    alg.Run()
+    alg.Finalize() # ensure output dataset is closed
+
+or
+
+.. code-block:: python
+
+    from osgeo import gdal
+    gdal.UseExceptions()
+    alg = gdal.GetGlobalAlgorithmRegistry()["raster"]["reproject"]
+    alg.ParseRunAndFinalize(["--input=in.tif", "--output=out.tif", "--dst-crs=EPSG:4326", "--co=TILED=YES,COMPRESS=DEFLATE", "--overwrite"])
+
+
+* Reprojecting a (possibly in-memory) dataset to a in-memory dataset
+
+.. code-block:: python
+
+    from osgeo import gdal
+    gdal.UseExceptions()
+    alg = gdal.GetGlobalAlgorithmRegistry()["raster"]["reproject"]
+    alg["input"] = input_ds
+    alg["output"] = "dummy_name"
+    alg["output-format"] = "MEM"
+    alg["dst-crs"] = "EPSG:4326"
+    alg.Run()
+    output_ds = alg["output"].GetDataset()
+
+
+
+Vector commands
+---------------
+
+* Getting information on a vector dataset as JSON
+
+.. code-block:: python
+
+    from osgeo import gdal
+    import json
+
+    gdal.UseExceptions()
+    alg = gdal.GetGlobalAlgorithmRegistry()["vector"]["info"]
+    alg["input"] = "poly.gpkg"
+    alg.Run()
+    info = json.loads(alg["output-string"])
+    print(info)
+
+
+* Converting a shapefile to a GeoPackage
+
+.. code-block:: python
+
+    from osgeo import gdal
+    gdal.UseExceptions()
+    alg = gdal.GetGlobalAlgorithmRegistry()["vector"]["convert"]
+    alg["input"] = "in.shp"
+    alg["output"] = "out.gpkg"
+    alg["overwrite"] = True  # if the output file may exist
+    alg.Run()
+    alg.Finalize() # ensure output dataset is closed
+
+or
+
+.. code-block:: python
+
+    from osgeo import gdal
+    gdal.UseExceptions()
+    alg = gdal.GetGlobalAlgorithmRegistry()["vector"]["convert"]
+    alg.ParseRunAndFinalize(["--input=in.shp", "--output=out.gpkg", "--overwrite"])

doc/source/programs/index.rst

@@ -26,6 +26,7 @@ single :program:`gdal` program that accepts commands and subcommands.
    :hidden:
 
    migration_guide_to_gdal_cli
+   gdal_cli_from_python
    gdal
    gdal_info
    gdal_convert
@@ -50,6 +51,7 @@ single :program:`gdal` program that accepts commands and subcommands.
 .. only:: html
 
     - :ref:`migration_guide_to_gdal_cli`: Migration guide to "gdal" command line interface
+    - :ref:`gdal_cli_from_python`: How to use "gdal" CLI algorithms from Python
     - :ref:`gdal_program`: Main "gdal" entry point
     - :ref:`gdal_info_command`: Get information on a dataset
     - :ref:`gdal_convert_command`: Convert a dataset