python - sqlalchemy.exc.ArgumentError : Can't load plugin: sqlalchemy. 方言:驱动程序

Question

我正在尝试运行 alembic 迁移以及何时运行

alembic revision --autogenerate -m "Added initial tables"

它失败了

sqlalchemy.exc.ArgumentError: Can't load plugin: sqlalchemy.dialects:driver

数据库地址是

postgresql+psycopg2://dev:passwd@localhost/db

我什至在我的 virtualenv 中安装了 psycopg2

$yolk -l
Flask-Login     - 0.1.3        - active
Flask-SQLAlchemy - 0.16         - active
Flask           - 0.9          - active
Jinja2          - 2.6          - active
Mako            - 0.7.3        - active
MarkupSafe      - 0.15         - active
Python          - 2.7.2        - active development (/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload)
SQLAlchemy      - 0.8.0        - active
Werkzeug        - 0.8.3        - active
alembic         - 0.4.2        - active
antiorm         - 1.1.1        - active
appscript       - 1.0.1        - active
distribute      - 0.6.27       - active
envoy           - 0.0.2        - active
osascript       - 0.0.4        - active
pep8            - 1.4.5        - active
pip             - 1.1          - active
psycopg2        - 2.4.6        - active
wsgiref         - 0.1.2        - active development (/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7)
yolk            - 0.4.3        - active

为什么会导致这个问题？

Answer 1

下面是如何产生这样的错误:

>>> from sqlalchemy import *
>>> create_engine("driver://")
Traceback (most recent call last):
... etc
sqlalchemy.exc.ArgumentError: Can't load plugin: sqlalchemy.dialects:driver

所以我想说你实际上并没有使用你认为的 postgresql URL - 你可能在某处调用默认生成的 alembic.ini。