Psycopg

Psycopg is the most popular PostgreSQL adapter for the Python programming language. At its core it fully implements the Python DB API 2.0 specifications.

Several extensions allow access to many of the features offered by PostgreSQL.
Psycopg is written mostly in C and wraps the libpq library with the result of being both fast and secure.
Features:
-Supports Python versions from 2.4 to 3.2
-Supports PostgreSQL versions from 7.4 to 9.1
-Fully compliant implementation of the Python DB API specification for database adapters
-Thread-safe: threads can use different connections or share the same connection
-Asynchronous nonblocking I/O, also integrated with coroutine-based libraries (gevent, Eventlet, uGreen)
-Includes the Zope Database Adapter ZPsycopgDA
-Adaptation of many Python objects to database type: tuples to records, lists to array, dictionaries to hstore
-Extendible with new adapters to convert Python objects to SQL syntax and typecasters to convert PostgreSQL types back into Python objects
-Server-side cursors
-COPY support
-Large objects support
-Can send and receive asynchronous notification
-Support for two-phase commit