PostgreSQL – Connecting to the database using Python
PostgreSQL API for Python allows user to interact with the PostgreSQL database using the psycopg2 module. In this article we will look into the process of connecting to a PostgreSQL database using Python.
First we will need to install the psycopg2 module with the below command in the command prompt:
pip install psycopg2
Creating a Database:
For the purpose of example we will be needing a sample database. To create so, follow the below steps:
- First open a PostgreSQL client tool like pgadmin4 or psql.
- Second login to the database using your credentials.
- Finally use the below command to create a database (say, School)
CREATE DATABASE school;
Connecting to the database:
To connect to the above created database (ie, school), we use the connect () function. The connect() function is used to create a new database session and it returns a new connection class instance.
To do so use the below syntax:
Syntax: conn = psycopg2.connect("dbname=suppliers user=postgres password=postgres")
To make it convenient to use you can use the below method:
1. First create a database.ini file with the credentials as shown below:
[postgresql] host=localhost database=school user=postgres password=5555
Now, the following config() function reads the database.ini file and returns connection parameters. The same config() function is added in the config.py file:
The following connect() function connects to the school database that we created earlier and returns the PostgreSQL database version.