Error while performing actions in GRASS GIS in Python

Question

While performing actions in python console as described in the module of GRASS GIS,am getting following error:

import grass.script as gs

r.in.gdal -e input="D:...\ASTGTMV003_N19E073_dem" output=DEM

File "", line 1

r.in.gdal -e input="D:\...\ASTGTMV003_N19E073_dem" output=DEM
 ^

SyntaxError: invalid syntax

Then I gave input from import raster and was able to view my DEM tile in GUI but the next actions gave me other errors.

gs.run_command('g.region', raster='elevation')

Traceback (most recent call last):

File "", line 1, in

File "C:\OSGEO4~1\apps\grass\grass78\etc\python\grass\script\core.py", line 441, in run_command return handle_errors(returncode, returncode, args, kwargs)

File "C:\OSGEO4~1\apps\grass\grass78\etc\python\grass\script\core.py", line 343, in handle_errors returncode=returncode)

grass.exceptions.CalledModuleError: Module run None g.region raster=elevation ended with error

Process ended with non-zero return code 1. See errors in the (error) output.

s.run_command('r.neighbors', input='elevation', output='elev_smoothed', method='average', flags='c')

Traceback (most recent call last):

File "", line 1, in

File "C:\OSGEO4~1\apps\grass\grass78\etc\python\grass\script\core.py", line 441, in run_command return handle_errors(returncode, returncode, args, kwargs)

File "C:\OSGEO4~1\apps\grass\grass78\etc\python\grass\script\core.py", line 343, in handle_errors returncode=returncode)

grass.exceptions.CalledModuleError: Module run None r.neighbors -c input=elevation output=elev_smoothed method=average ended with error

Process ended with non-zero return code 1. See errors in the (error) output.

Answer 1

Several questions here. I'll try one by one...

r.in.gdal -e input="D:...\ASTGTMV003_N19E073_dem" output=DEM
File "", line 1
r.in.gdal -e input="D:\...\ASTGTMV003_N19E073_dem" output=DEM
 ^

This GRASS command must be run at the command prompt. Not in a python shell.

gs.run_command('g.region', raster='elevation')

Above you imported your Aster DEM as "DEM", but here you refer to "elevation". Is there a mixup of raster names?

s.run_command('r.neighbors', input='elevation', output='elev_smoothed', method='average', flags='c')

Possibly the same mixup in raster names?

In general, I would suggest to first run these commands at the GRASS prompt, to make sure you have the syntax right, Then move over to python.

• markusN: An alternative is using pyGRASS. Example: r.in_gdal(input=L7f,output=L7r,flags="e",overwrite=OVR) , see grasswiki.osgeo.org/wiki/Python/pygrass
• Omkar Kadlag: Thanks @Micha ,it was really helpful.