SQLAlchemy is an open source SQL toolkit and object-relational mapper (ORM) for the Python programming language released under the MIT License.
SQLAlchemy provides "a full suite of well known enterprise-level persistence patterns, designed for efficient and high-performing database access, adapted into a simple and Pythonic domain language". SQLAlchemy's philosophy is that SQL databases behave less and less like object collections the more size and performance start to matter, while object collections behave less and less like tables and rows the more abstraction starts to matter. For this reason it has adopted the data mapper pattern (like Hibernate for Java) rather than the active record pattern used by a number of other object-relational mappers. However, optional plugins such as Elixir and declarative allow users to develop using declarative syntax.
SQLAlchemy was first released in February, 2006 and has quickly become one of the most widely used object-relational mapping tools alongside Django's ORM in the Python community.
Read more about SQLAlchemy: Example