Question: I am working on psycopg 3 and not 2. Here is my code that I am trying to work on: from fastapi import FastAPI, Response, status, HTTPException from fastapi.params import Body from pydantic import BaseModel from typing import Optional from random import randrange import psycopg import psycopg2 from psycopg2.extras import RealDictCursor import time app = FastAPI() while True: try: conn = psycopg.connect(host = 'localhost', database = 'fastapi', user = 'postgres', password = 'islamabad', cursor_factory=RealDictCursor) cursor = conn.cursor() print("Database successfully connected!") break except Exception as error: print("Connection Failed") print("Error: ", error) time.sleep(2)  But I am getting the following error: ImportError: no pq wrapper available. Attempts made: - couldn't import psycopg 'c' implementation: No module named 'psycopg_c' - couldn't import psycopg 'binary' implementation: No module named 'psycopg_binary' - couldn't import psycopg 'python' implementation: libpq library not found  So I read somewhere to install psycopg[c] and psycopg[binary] Now when I am installing psycopg[c] it is giving the following error:  Using cached psycopg-c-3.1.2.tar.gz (616 kB) Installing build dependencies ... done Getting requirements to build wheel ... done Preparing metadata (pyproject.toml) ... error error: subprocess-exited-with-error × Preparing metadata (pyproject.toml) did not run successfully. │ exit code: 1 ╰─> [6 lines of output] running dist_info writing C:\Users\themr\AppData\Local\Temp\pip-modern-metadata-cr8kpz5q\psycopg_c.egg-info\PKG-INFO writing dependency_links to C:\Users\themr\AppData\Local\Temp\pip-modern-metadata-cr8kpz5q\psycopg_c.egg-info\dependency_links.txt writing top-level names to C:\Users\themr\AppData\Local\Temp\pip-modern-metadata-cr8kpz5q\psycopg_c.egg-info\top_level.txt couldn't run 'pg_config' --includedir: [WinError 2] The system cannot find the file specified error: [WinError 2] The system cannot find the file specified [end of output] note: This error originates from a subprocess, and is likely not a problem with pip. error: metadata-generation-failed × Encountered error while generating package metadata. ╰─> See above for output. note: This is an issue with the package mentioned above, not pip. hint: See above for details.  I can instead work on psycopg2 which is working but I want to shift to the new version. So, help out please!

Answer: There are 3 ways of installing psycopg 3:  Binary installation  This method will install a self-contained package with all the libraries required to connect python to your Postgres database. Install packages by running: pip install "psycopg[binary]"   Local installation  To use psycopg for a production site, this is the most preferred way of installing the psycopg adapter. Install packages by running: pip install "psycopg[c]"  3)Pure python installation In case you want to use pycopg for a test environment and for debugging purposes, use this method of installation. Install packages by running: pip install psycopg  To use the pure python installation, your system must contain the libpq library. libpq library is what the PostgreSQLcommand line client uses to connect to the database. Install the library by running: sudo apt install libpq5  Based on your code it seems that you are working on the python API development course. It would be best to use the 3rd method of installation as i assume you are using it for learning purposes. Therefore your code should look something like this: from typing import Optional from fastapi import Body, FastAPI, Response, status, HTTPException from pydantic import BaseModel from random import randrange import psycopg #from psycopg import ClientCursor import time app = FastAPI() try: conn = psycopg.connect(dbname='fastapi',user='postgres',password='islamabad', cursor_factory=RealDictCursor) cursor = conn.cursor() print("Database connection successful!") break except Exception as error: print("Connection failed") print("Error: ", error) time.sleep(2)  For more information kindly check the docs at: https://www.psycopg.org/psycopg3/docs/basic/install.html