SQLAlchemy with Python 64-bit on Windows

While hooking up SQLAlchemy for a web project, I kept running into attribute errors for ‘session_registry’. I figured I was doing something wrong, so I thought I’d just walk through the tutorial as a sanity check.

I was, apparently, insane.

>>> u = session.query(User).filter_by(name='ed').first()
Traceback (most recent call last):
File "", line 1, in
File "C:\dev\misc\SundanceAPI\sapi_env\lib\site-packages\sqlalchemy\orm\query.py", line 2282, in first
ret = list(self[0:1])
File "C:\dev\misc\SundanceAPI\sapi_env\lib\site-packages\sqlalchemy\orm\query.py", line 2149, in __getitem__
return list(res)
File "C:\dev\misc\SundanceAPI\sapi_env\lib\site-packages\sqlalchemy\orm\query.py", line 2349, in __iter__
context = self._compile_context()
File "C:\dev\misc\SundanceAPI\sapi_env\lib\site-packages\sqlalchemy\orm\query.py", line 2702, in _compile_context
context = QueryContext(self)
File "C:\dev\misc\SundanceAPI\sapi_env\lib\site-packages\sqlalchemy\orm\query.py", line 3247, in __init__
self.session = query.session_registry
AttributeError: 'Query' object has no attribute 'session_registry'

Tom Christensen, after joining me in some head scratching, noticed that I was on the 64-bit build of Python, and wondered if there could be anything strange with that.

Googling, we found:

TODO: Still valid? The ez_setup.py script currently(?) installs a broken version of setuptools on 64-bit Windows systems.

TODO: Still valid? To work around this you need to manually download SQLAlchemy and extract it. When extracted you need to copy the <top_dir>/lib/sqlalchemy directory into your Python<version>\Lib\site-packages directory.

Sure enough, following that work-around got rid of the errors. So thanks, openlp guys. In the end, I swapped my virtual environment out for the 32-bit variety. It feels safer there.

Leave a Reply

Your email address will not be published. Required fields are marked *