Replicating ogr2ogr operation with GDAL vector translate

Question

Following a comment on Error using SQL statement in ogr2ogr with Python string formatter, I am trying to use gdal.VectorTranslate() instead of ogr2ogr, but I keep receiving an error.

Using Windows, Python 3.7, and GDAL 3.3.1.

The following ogr2ogr approach works fine.

import os
import numpy as np
import pathlib
example dummy ids
id1 = np.linspace(start=1, stop=5, num=5, endpoint=True, dtype=int)
id2 = np.linspace(start=301, stop=302, num=2, endpoint=True, dtype=int)
outpath = pathlib.Path("working").resolve()
for ii in id1:
    command = (
        ' ogr2ogr -f "KML" "{outfile}" "{infile}" '
        ' -where "ID_1 = {my_id}" '
        ' -dsco NameField = "{name}" '
    )
    fout = 'test' + str(ii) + '.kml'
    fout = outpath / fout
    os.system(command.format(outfile=fout, infile='points.shp', my_id=ii, name='county'))

But trying gdal.VectorTranslate() based on the documentation for VectorTranslate and VectorTranslateOptions here throws the error as shown. I want to try this approach to see if it passes SQL statements easier than the -sql option in ogr2ogr.

for ii in id1:
    command = (
        ' ogr2ogr -f "KML" "{outfile}" "{infile}" '
        ' -where "ID_1 = {my_id}" '
        ' -dsco NameField = "{name}" '
    )
    fout = 'test' + str(ii) + '.kml'
    fout = outpath / fout
    args = gdal.VectorTranslateOptions(
        format="KML",
        SQLStatement=command.format(outfile=fout, infile='points.shp', my_id=ii, name='county')
    )
    gdal.VectorTranslate(
        destNameOrDestDS=fout,
        srcDS=shpecs,
        options=args
    )

Error:

C:\Users\name\anaconda3\envs\myenv\python.exe "D:/Documents/test.py"
Traceback (most recent call last):
D:\Documents\points
  File "D:/Documents/test.py", line 51, in <module>
    options=args
D:\Documents\working
  File "C:\Users\name\anaconda3\envs\myenv\lib\site-packages\osgeo\gdal.py", line 857, in VectorTranslate
    return wrapper_GDALVectorTranslateDestDS(destNameOrDestDS, srcDS, opts, callback, callback_data)
  File "C:\Users\name\anaconda3\envs\myenv\lib\site-packages\osgeo\gdal.py", line 4625, in wrapper_GDALVectorTranslateDestDS
    return _gdal.wrapper_GDALVectorTranslateDestDS(*args)
TypeError: in method 'wrapper_GDALVectorTranslateDestDS', argument 1 of type 'GDALDatasetShadow *'

I receive the same error if I pass the options directly into VectorTranslate.

Answer 1

Here's how to use gdal.VectorTranslate, note that some ogr2ogr options map to slightly different arguments, but they should be easily figured out:

from osgeo import gdal
import numpy as np
import pathlib
gdal.UseExceptions()
example dummy ids
id1 = np.linspace(start=1, stop=1, num=1, endpoint=True, dtype=int)
id2 = np.linspace(start=1, stop=1, num=1, endpoint=True, dtype=int)
infile = '/tmp/points.shp'
inlayer = pathlib.Path(infile).stem
outpath = pathlib.Path("/tmp").resolve()
name_field = 'county'
for ii in id1:
    for jj in id2:
        fout = str(outpath / f'test{ii}_{jj}.kml')
    ds = gdal.VectorTranslate(
        fout, infile,
        # SQLStatement=f'SELECT * from {inlayer} WHERE ID_1 = {ii} AND ID_2 = {jj}',
        where=f'ID_1 = {ii} AND ID_2 = {jj}',
        datasetCreationOptions=[f'NameField={name_field}'],
        layers=[inlayer],
        format='KML'
    )

Note:

• I've changed your -sql argument clause to a simpler -where argument
• I used f'string {variable}' aka "f strings" for a cleaner syntax