Checking sqlite connection error in sqlalchemy
On Python versions < 3.4 (including Python 2.7) you can't prevent SQLite from creating the file for you when you connect to a SQLite database file that doesn't yet exist.
So on older Python versions you'll have to use different means to test for the existence of the file first. A simple os.path.exists should suffice:
import os.pathdatabase = '/path/to/database.db'if not os.path.exists(database): raise ValueError('Invalid database path: %s' % (database,)db = sqlalchemy.create_engine('sqlite:///' + database)On newer Python versions, the sqlite3 library supports the SQLite URI syntax, so you can specify a mode=rw parameter to disable the default rwc (read-write-create) mode, provided you set uri=True on the sqlite3.connect() call.
SQLAlchemy doesn't support SQLite URI parameters (yet), but you can make use of the creator parameter to pass in the URI flag and your own connection string:
import sqlite3uri = 'file:/path/to/database.db?mode=rw'creator = lambda: sqlite3.connect(uri, uri=True)db = sqlalchemy.create_engine('sqlite:////', creator=creator)