alembic and sqlalchemy are not only on par with django's tools, they are generally superior. This isn't just my opinion, here's Alex Gaynor, Django core committer, saying the same thing:

https://speakerdeck.com/u/alex/p/why-i-hate-the-django-orm

Yet the developmental resources SQLAlchemy and Alembic are a tiny fraction of what Django has. It's the tremendous gravitational pull of Django and the habits of its community writing things hardcoded to Django that suck the life out of other projects in the Python community.