Question

I would like to see more error messages in the Python shell from GDAL, but I can’t seem to figure it out how to capture them (where they exist). For example, opening a GeoTIFF file that does not exist:

from osgeo import gdal
ds = gdal.Open('noexist.tif')

shows absolutely nothing on an interactive Python shell (PythonWin or IDLE). However, if these commands are run in a system shell (Bash, cmd.exe, etc) or save this as a showit.py file, a “hidden” error message is reviled:

C:\>c:\Python32\python.exe showit.py
ERROR 4: `noexist.tif' does not exist in the file system,
and is not recognised as a supported dataset name.

This is a useful error message sent to stderr of the system shell. Any ideas how this can also be shown in the Python interactive shell, or be captured in general?

Answer 1

Check out the python gdal gotchas. I believe that you can get this working by simply calling gdal.UseExceptions() after your initial import. Like so:

from osgeo import gdal
gdal.UseExceptions()
gdal.Open('myfile.tif")

Source: http://trac.osgeo.org/gdal/wiki/PythonGotchas