Just as a note to everyone, you can use Mako/Jinja2, SQLAlchemy and really any other Python tool/library out there with Django.
What Django does well is provide a pre-built and (IMHO) easy to use set of default tools. This does not mean that you must use these tools, they are just there by default if you need them. You could really just use Django as an HTTP routing tool.
I admit it's been a while, but when I tried django-sqlalchemy in the past, it was not in a pleasant state. Last I came around, it was certainly not just a simple drop-in thing.
While I'm sure you're right that it's not a hard requirement in that you can figure out how to make it work, it's not an easy thing, and you'll be fighting the framework and the conventions all along the way as interdependent stuff stops working. Again, in my experience. If things have improved significantly, I'd like to know.
When toys ship "batteries included", it's easy to pull them out and replace with a different brand, if you want. Django, and most other web frameworks, don't make that interoperability a serious concern, afaik. When you use a framework, you are essentially adopting its code into your project all at once, and you become responsible to make sure it works and adapts to your needs even if upstream dies out or makes a decision that renders new versions unusable for your use case. "Non-removable batteries" are therefore a major design flaw in your project, even if you haven't had occasion for it to be exposed yet. The batteries of monolithic, "opinionated" web frameworks like Rails and Django may be partially removable, and maybe they've improved recently, but newer frameworks like Flask and Pyramid don't have this issue at all, and it makes them much more flexible.
Just wondering if you have any tips (that you recall) for making django and sql alchemy work together. sql alchemy seems like the best ORM to work with and django has a nice ecosystem. If sql alchemy only does read operations on django models, will that make the integration simpler?
What Django does well is provide a pre-built and (IMHO) easy to use set of default tools. This does not mean that you must use these tools, they are just there by default if you need them. You could really just use Django as an HTTP routing tool.