What is psycopg2?

Psycopg2 is a Python library that lets Python programs connect to and communicate with a PostgreSQL database. PostgreSQL is a popular open-source relational database, and psycopg2 is the most widely used way to talk to it from Python code. It handles the translation between Python data and database operations: your Python script can run SQL queries, insert or update rows, and read results back as Python objects. The library is written mostly in C, which makes it fast and memory-efficient compared to a pure-Python implementation. It is built on top of libpq, the official PostgreSQL client library. It supports running multiple operations from different threads at the same time without conflicts, which matters in web applications or other programs that handle many simultaneous requests. It follows the Python DB API 2.0 standard, a shared interface specification that most Python database libraries implement. This means if you have used a different database library in Python before, the basic patterns will look familiar. Features include client-side and server-side cursors, support for bulk data transfer using PostgreSQL's COPY command, and automatic conversion between common Python types and their PostgreSQL equivalents. Installation is a single pip command. There is also a binary variant called psycopg2-binary that skips the compilation step and is easier to install for development, though the compiled-from-source version is recommended for production use. The README notes that psycopg2 is still maintained but will not receive new features. A successor called Psycopg 3 is where active development is happening, and new projects are encouraged to start there instead.