问SQLAlchemy无法连接本地主机上的Postgresql

EN

11:58:18 web.1  | ERROR:xxxxxx.core:Exception on / [GET]
11:58:18 web.1  | Traceback (most recent call last):
11:58:18 web.1  |   File "/Library/Python/2.7/site-packages/flask/app.py", line 1817, in wsgi_app
11:58:18 web.1  |     response = self.full_dispatch_request()
11:58:18 web.1  |   File "/Library/Python/2.7/site-packages/flask/app.py", line 1477, in full_dispatch_request
11:58:18 web.1  |     rv = self.handle_user_exception(e)
11:58:18 web.1  |   File "/Library/Python/2.7/site-packages/flask/app.py", line 1381, in handle_user_exception
11:58:18 web.1  |     reraise(exc_type, exc_value, tb)
11:58:18 web.1  |   File "/Library/Python/2.7/site-packages/flask/app.py", line 1475, in full_dispatch_request
11:58:18 web.1  |     rv = self.dispatch_request()
11:58:18 web.1  |   File "/Library/Python/2.7/site-packages/flask/app.py", line 1461, in dispatch_request
11:58:18 web.1  |     return self.view_functions[rule.endpoint](**req.view_args)
11:58:18 web.1  |   File "xxxxxxx/web.py", line 202, in home
11:58:18 web.1  |     d = {'featured': cached_apps.get_featured_front_page(),
11:58:18 web.1  |   File "/Library/Python/2.7/site-packages/flask_cache/__init__.py", line 245, in decorated_function
11:58:18 web.1  |     rv = f(*args, **kwargs)
11:58:18 web.1  |   File "/Users/xxxxxxx/Desktop/PythonProjects/xxxxxx/xxxxxx2/xxxxxxx/cache/apps.py", line 35, in get_featured_front_page
11:58:18 web.1  |     results = db.engine.execute(sql)
11:58:18 web.1  |   File "/Library/Python/2.7/site-packages/flask_sqlalchemy/__init__.py", line 780, in engine
11:58:18 web.1  |     return self.get_engine(self.get_app())
11:58:18 web.1  |   File "/Library/Python/2.7/site-packages/flask_sqlalchemy/__init__.py", line 797, in get_engine
11:58:18 web.1  |     return connector.get_engine()
11:58:18 web.1  |   File "/Library/Python/2.7/site-packages/flask_sqlalchemy/__init__.py", line 470, in get_engine
11:58:18 web.1  |     self._sa.apply_driver_hacks(self._app, info, options)
11:58:18 web.1  |   File "/Library/Python/2.7/site-packages/flask_sqlalchemy/__init__.py", line 739, in apply_driver_hacks
11:58:18 web.1  |     if info.drivername.startswith('mysql'):
11:58:18 web.1  | AttributeError: 'NoneType' object has no attribute 'drivername'

/Applications/Postgres.app/Contents/MacOS/bin/psql

/Applications/Postgres.app/Contents/MacOS/bin/postgres

[alembic]
# path to migration scripts
script_location = alembic

# template used to generate migration files
# file_template = %%(rev)s_%%(slug)s

# under Heroku, the line below needs to be inferred from
# the environment
sqlalchemy.url = postgres://xxxxxxxxxx:xxxxxxxxxxxx@xxxxxx.compute-1.amazonaws.com:5432/xxxxxxxxx

# Logging configuration
[loggers]
keys = root,sqlalchemy,alembic

#!/usr/bin/env python
import os
import sys
import optparse
import inspect

import xxxxxxx.model as model
from xxxxxx.core import db
import xxxxx.web as web

from alembic.config import Config
from alembic import command    
def setup_alembic_config():
    if "DATABASE_URL" not in os.environ:
        alembic_cfg = Config("alembic.ini")
    else:
        dynamic_filename = "alembic-heroku.ini"
        with file("alembic.ini.template") as f:
            with file(dynamic_filename, "w") as conf:
                for line in f.readlines():
                    if line.startswith("sqlalchemy.url"):
                        conf.write("sqlalchemy.url = %s\n" %
                                   os.environ['DATABASE_URL'])
                    else:
                        conf.write(line)
        alembic_cfg = Config(dynamic_filename)

    command.stamp(alembic_cfg, "head")

def db_create():
    '''Create the db'''
    db.create_all()
    # then, load the Alembic configuration and generate the
    # version table, "stamping" it with the most recent rev:
    setup_alembic_config()
    # finally, add a minimum set of categories: Volunteer Thinking, Volunteer Sensing, Published and Draft
    categories = []
    categories.append(model.Category(name="Thinking",
                                     short_name='thinking',
                                     description='Volunteer Thinking apps'))
    categories.append(model.Category(name="Volunteer Sensing",
                                     short_name='sensing',
                                     description='Volunteer Sensing apps'))
    db.session.add_all(categories)
    db.session.commit()

Traceback (most recent call last):
  File "cli.py", line 111, in <module>
    _main(locals())
  File "cli.py", line 106, in _main
    _methods[method](*args[1:])
  File "cli.py", line 33, in db_create
    db.create_all()
  File "/Library/Python/2.7/site-packages/flask_sqlalchemy/__init__.py", line 856, in create_all
    self._execute_for_all_tables(app, bind, 'create_all')
  File "/Library/Python/2.7/site-packages/flask_sqlalchemy/__init__.py", line 848, in _execute_for_all_tables
    op(bind=self.get_engine(app, bind), tables=tables)
  File "/Library/Python/2.7/site-packages/flask_sqlalchemy/__init__.py", line 797, in get_engine
    return connector.get_engine()
  File "/Library/Python/2.7/site-packages/flask_sqlalchemy/__init__.py", line 470, in get_engine
    self._sa.apply_driver_hacks(self._app, info, options)
  File "/Library/Python/2.7/site-packages/flask_sqlalchemy/__init__.py", line 739, in apply_driver_hacks
    if info.drivername.startswith('mysql'):
AttributeError: 'NoneType' object has no attribute 'drivername'