support.py

# setup the db
from master import app
from flask.ext.sqlalchemy import SQLAlchemy

db = SQLAlchemy(app)

# XXX HACK
#
# Sqlite's DATETIME type doesn't support timezones, but in production
# we use postgres which does. So when we're using sqlite and pulling
# a datetime from the database, we force the value to take on the
# local timezone.

from sqlalchemy.dialects.sqlite.base import DATETIME
from dateutil.tz import tzlocal

old_processor = DATETIME.result_processor

def new_processor(self, *args, **kwargs):
    def processor(value):
        dt = old_processor(self, *args, **kwargs)(value)
        if dt and dt.tzinfo is None:
            dt = dt.replace(tzinfo=tzlocal())
        return dt

    return processor

DATETIME.result_processor = new_processor

$ python
>>> from common.support import db
>>> db.create_all()
2015-05-05 03:47:27,826 1801   userid:- sqlalchemy.engine.base.Engine INFO     select version()
2015-05-05 03:47:27,827 1801   userid:- sqlalchemy.engine.base.Engine INFO     {}
2015-05-05 03:47:27,829 1801   userid:- sqlalchemy.engine.base.Engine INFO     select current_schema()
2015-05-05 03:47:27,830 1801   userid:- sqlalchemy.engine.base.Engine INFO     {}
2015-05-05 03:47:27,833 1801   userid:- sqlalchemy.engine.base.Engine INFO     show standard_conforming_strings
2015-05-05 03:47:27,834 1801   userid:- sqlalchemy.engine.base.Engine INFO     {}