How to install 3rd party module for postgres pl/python?

Question

I need to import a 3rd party module inside my pl/python function. It seems pl/python uses an internal python that does not have any 3rd party modules.

I get this kind of error:

ERROR:  PL/Python: PL/Python function "to_tsvector_luc" failed
DETAIL:  <type 'exceptions.ImportError'>: No module named lucene

********** Error **********

ERROR: PL/Python: PL/Python function "to_tsvector_luc" failed
SQL state: XX000
Detail: <type 'exceptions.ImportError'>: No module named lucene

How do I install the module into pl/python, so that I can import it from inside my stored procedure code?

Answer 1

pl/python has access to the all the modules that the normal Python interpreter would have as long as they are in the $PYTHONPATH on the server (and the user that runs the postgres service). Does import lucene work if you run it in the Python interpreter on the server?

If your module is installed somewhere else (e.g. not dist-packages etc.), then you would need to edit your /etc/postgresql/9.1/main/environment (adjust to your PostgreSQL version) file on the server and add something like PYTHONPATH='<path to your module>'.

Answer 2

Since modifying PYTHONPATH of postgres user will likely need a server restart, it's somewhat easier to add the path from within Python, via

from sys import path
path.append( '/path/to/your/module' )