Question

I know this might be really a simple question but I don’t know the solution. What is happening here when I try to connect to postgresql? I am self learner in this field of database and programming so please be gentle with me.
When I try following code:

import sqlalchemy
db = sqlalchemy.create_engine('postgresql:///tutorial.db')

I get this error:

Traceback (most recent call last):
File “”, line 1, in
db = sqlalchemy.create_engine(‘postgresql:///tutorial.db’)
File “C:\Python27\lib\site-packages\sqlalchemy-0.7.5dev-py2.7.egg\sqlalchemy\engine__init__.py”, line 327, in create_engine
return strategy.create(*args, **kwargs)
File “C:\Python27\lib\site-packages\sqlalchemy-0.7.5dev-py2.7.egg\sqlalchemy\engine\strategies.py”, line 64, in create
dbapi = dialect_cls.dbapi(**dbapi_args)
File “C:\Python27\lib\site-packages\sqlalchemy-0.7.5dev-py2.7.egg\sqlalchemy\dialects\postgresql\psycopg2.py”, line 289, in dbapi
psycopg = import(‘psycopg2’)
ImportError: No module named psycopg2

Do I need to install psycopg2 separately? What is the correct connection string for postgresql?

Answer 1

Yes, psycopg2 are basically the Python drivers for PostgreSQL that need to be installed separately.

A list of valid connection strings can be found here, yours is a bit off (you need to the username, the password and hostname as specified in the link below):

http://docs.sqlalchemy.org/en/latest/core/engines.html#postgresql