I suggest running a test script that reports sys.path to confirm that the actual Python module search path seen by the Postgres server's environment is as expected.
-------------------------> "These thoughts are mine alone!" <--------- Andrew MacIntyre Operations Branch tel: +61 2 6219 5356 Communications Infrastructure Division fax: +61 2 6253 3277 Australian Communications & Media Authority email: [email protected] http://www.acma.gov.au/ > Message: 5 > Date: Wed, 18 Jul 2012 22:58:59 +1000 > From: Mark Wynter <[email protected]> > To: [email protected] > Subject: [GRASS-user] Problem accessing GRASS from > PostgreSQL9.1/PostGIS2.0 via pg-python or plpythonu > Message-ID: <4D8125BB-F64C-4D07-8D4B- > [email protected]> > Content-Type: text/plain; charset="utf-8" > > My requirement is to connect to GRASS from PostgreSQL9.1/PostGIS2.0 via > the pg-python or plpythonu procedural language. I'm wondering whether I > have a permissions issue? > > I'm running my stack on Ubuntu 12.04 LTS > I've added the following environmental variables to /etc/bash.bashrc > export GISBASE=/usr/local/grass-6.4.3svn > export PATH=$PATH:$GISBASE/bin:$GISBASE/scripts:$GISBASE/lib > export PYTHONPATH=${PYTHONPATH}:$GISBASE/etc/python/ > export PYTHONPATH=${PYTHONPATH}:$GISBASE/etc/python/grass > export PYTHONPATH=${PYTHONPATH}:$GISBASE/etc/python/grass/script > export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$GISBASE/lib > export GIS_LOCK=$$ > export GISRC=$HOME/.grassrc6 > > If I log out and log in again, the following environment variables are now > available to the postgres user: > > ubuntu@ip-10-252-74-140:~$ sudo su postgres > postgres@ip-10-252-74-140:/home/ubuntu$ echo $GISBASE > /usr/local/grass-6.4.3svn > postgres@ip-10-252-74-140:/home/ubuntu$ echo $PYTHONPATH > :/usr/local/grass-6.4.3svn/etc/python/:/usr/local/grass- > 6.4.3svn/etc/python/grass:/usr/local/grass-6.4.3svn/etc/python/grass/script > postgres@ip-10-252-74-140:/home/ubuntu$ echo $HOME > /var/lib/postgresql > > > if I call the function "import grass.script as grass" from the python console, > there is no error. All seems ok. > > postgres@ip-10-252-74-140:/$ python > Python 2.7.3 (default, Apr 20 2012, 22:39:59) > [GCC 4.6.3] on linux2 > Type "help", "copyright", "credits" or "license" for more information. > >>> import grass.script as grass > >>> > > If I now log into PostgreSQL/PostGIS via psql, and try to run the same > command within in a postgresql plpythonu or pg-python function, I get the > following error messages. > psql -d test > > CREATE OR REPLACE FUNCTION pythontest() RETURNS text AS > $$ > import grass.script as grass > $$ > LANGUAGE 'plpythonu' VOLATILE; > > test=# select pythontest(); > ERROR: ImportError: No module named grass.script > CONTEXT: Traceback (most recent call last): > PL/Python function "pythontest", line 3, in <module> > import grass.script as grass > PL/Python function "pythontest" > test=# > > I've also tried the pg-python language - in case it had something to do with > plpythonu: > > CREATE OR REPLACE FUNCTION pgpython_test() > RETURNS text LANGUAGE python AS > $python$ > import Postgres > import grass.script as grass > def main(): > return ("Hello World") > $python$; > > > test=# select pgpython_test(); > ERROR: could not load Python function's module object > CONTEXT: [exception from Python] > Traceback (most recent call last): > File "public.pgpython_test()", line 3, in <module> > ImportError: No module named grass.script > > [public.pgpython_test() while loading function module] > test=# > > I can however access GRASS from PostgreSQL9.1/PostGIS2.0 via pl/r and R. > For example, this function works... > CREATE OR REPLACE FUNCTION generate_viewshed() RETURNS text as > $$ > library(spgrass6) > #initialise GRASS. > initGRASS(gisBase = ?/usr/local/grass-6.4.3svn/?, home = tempdir(), > gisDbase = ?/usr/local/share/grassdata/?, location = > ?aust_dem_1sec_wgs84?, mapset = ?postgres?, SG=?aust_dem_1sec?, > override = TRUE) > #define the computational region for the analysis ? limiting the region to an > area slightly greater than the max_distance from the observation point. > execGRASS(?g.region?, parameters = list(n=?-34.9759927736275?, s=?- > 34.9985728860995?, e=?138.641896696527?, w=?138.619947232807?, > align=?aust_dem_1sec?)) > #run the viewshed module ? all of these parameters can be set dynamically > and parsed as plr function arguments ? the output is a raster file. > execGRASS(?r.viewshed?, parameters = list(input = ?aust_dem_1sec?, > output = ?viewshed_raster?, coordinate = ?138.630922,-34.987283?, > obs_elev = 25, max_dist = 1000), flags = c(?b?, ?overwrite?)) > #convert the raster output to a vector. > execGRASS(?r.to.vect?, parameters = list(input = ?viewshed_raster?, output > = ?viewshed_vector?, feature = ?area?), flags = c(?overwrite?)) > #write the vector data back to PostGIS. > execGRASS(?v.out.ogr?, parameters = list(input = ?viewshed_vector?, dsn = > ?PG:host=localhost dbname=test user=postgres password=password?, > olayer = ?viewshed_vector?, format = ?PostgreSQL?, type = ?area?), flags = > c(?c?)) > $$ > LANGUAGE ?plr?; > > In terms of GRASS permissions... > postgres@ip-10-252-74-140:/home/ubuntu$ vi $HOME/.grassrc6 > GISDBASE: /usr/local/share/grassdata > LOCATION_NAME: aust_dem_1sec_wgs84 > MAPSET: postgres > GRASS_GUI: text > ~ > > This is as far as I've got and need some help to connect to GRASS from > PostgeSQL/PostGIS via python (as an alternative to pl/r). > Is there something obvious I have missed? Could someone please guide me > through to a solution. > > With thanks and regards > > Mark > > > > > > > > > > > > > > > > > > > > > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: <http://lists.osgeo.org/pipermail/grass- > user/attachments/20120718/0778037e/attachment.html> > > ------------------------------ > > _______________________________________________ > grass-user mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/grass-user > > > End of grass-user Digest, Vol 75, Issue 31 > ****************************************** NOTICE: This email message is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. 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