DB Wiki

psycopg

Connecting to PostgreSQL

import psycopg2
import psycopg2.extras
 
conn = psycopg2.connect(database="doob", user = "ian", password = "pwd", host = "localhost")
print "Connection Successful"
 
#cur = conn.cursor()
cur = conn.cursor(cursor_factory=psycopg2.extras.DictCursor)
 
query = "SELECT usename, usesuper FROM pg_user"
cur.execute(query)
 
rows = cur.fetchall()
 
for row in rows:
  print(row)
  print(f"{row['usename']} {row['usesuper']}")
 
cur.close()

Example Connection Files

Using Config Parser

# database.ini
[postgresql]
host=localhost
database=doob
user=ian
password=pwd

#!/usr/bin/python
from configparser import ConfigParser
 
def config(filename='database.ini', section='postgresql'):
  parser = ConfigParser()
  parser.read(filename)
  params = parser.items(section)
  for param in params:
    db[param[0]] = param[1]
 
  return db

#!/usr/bin/python
from config import config
 
def connect()
  conn = None
  try:
    params = config()
    conn = psycopg2.connect(**params)
    cur = conn.cursor()
    cur.execute('SELECT version()')
    db_version = cur.fetchone()
    print(db_version)
    cur.close()
  except (Exception, psycopg2.DatabaseError) as error:
    print(error)

Using Credential File

# conndetails.py
PGHOST="localhost"
PGDATABASE="doob"
PGUSER="ian"
PGPASSWORD="pwd"

import psycopg2
import conndetails as creds
 
conn_string = "host="+ creds.PGHOST +" dbname="+ creds.PGDATABASE +" user=" 
               + creds.PGUSER +" password="+ creds.PGPASSWORD
conn = psycopg2.connect(conn_string)
 
cur = conn.cursor()
query = "select version()"
cur.execute(query)
for row in cur:
  print(row)
 
cur.close()