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psycopg/psycopg2

Analysis updated 2026-05-18

3,630CAudience · developerComplexity · 2/5Setup · easy

TLDR

The most widely used Python library for connecting to and querying a PostgreSQL database, written in C for speed and built on the official libpq client.

Mindmap

mindmap
  root((psycopg2))
    What it does
      Connects Python to PostgreSQL
      Runs SQL queries
    Tech stack
      C
      libpq
      Python DB API 2.0
    Features
      Client and server cursors
      COPY bulk transfer
      Thread safe
    Use cases
      Web app database access
      Data pipelines
    Audience
      Python developers

Code map

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What do people build with it?

USE CASE 1

Connect a Python web application to a PostgreSQL database and run queries.

USE CASE 2

Bulk load or export data using PostgreSQL's COPY command from Python.

USE CASE 3

Handle many simultaneous database requests safely using multiple threads.

USE CASE 4

Migrate a project already using another DB API 2.0 library to PostgreSQL.

What is it built with?

PythonCPostgreSQLlibpq

How does it compare?

psycopg/psycopg2sandboxie/sandboxielittlekernel/lk
Stars3,6303,6333,634
LanguageCCC
Setup difficultyeasymoderatehard
Complexity2/53/55/5
Audiencedeveloperops devopsdeveloper

Figures from each repo's GitHub metadata at analysis time.

How do you get it running?

Difficulty · easy Time to first run · 30min

Single pip install, source build requires PostgreSQL dev headers, so psycopg2-binary is easier for local development.

In plain English

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.

Copy-paste prompts

Prompt 1
Show me how to install psycopg2 with pip and connect to a PostgreSQL database from Python.
Prompt 2
Explain the difference between psycopg2 and psycopg2-binary and when to use each.
Prompt 3
Help me write a Python script using psycopg2 to run a query and read back the results.
Prompt 4
Should I use psycopg2 or Psycopg 3 for a new project, based on what this README says?

Frequently asked questions

What is psycopg2?

The most widely used Python library for connecting to and querying a PostgreSQL database, written in C for speed and built on the official libpq client.

What language is psycopg2 written in?

Mainly C. The stack also includes Python, C, PostgreSQL.

How hard is psycopg2 to set up?

Setup difficulty is rated easy, with roughly 30min to a first successful run.

Who is psycopg2 for?

Mainly developer.

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