Create a Postgres database using python

I want to create Postgres database using Python.

con = psql.connect(dbname='postgres',
      user=self.user_name, host='',
      password=self.password)

cur = con.cursor()
cur.execute("CREATE DATABASE %s  ;" % self.db_name)

I am getting the following error:

InternalError: CREATE DATABASE cannot run inside a transaction block

I am using psycopg2 to connect. I don't understand what's the problem. What am I trying to do is to connect to database (Postgres):

psql -postgres -U UserName

And then create another database:

create database test;

This is what I usually do and I want to automate this by creating Python script.

Use ISOLATION_LEVEL_AUTOCOMMIT, a psycopg2 extensions:

> No transaction is started when command are issued and no commit() or > rollback() is required.

import psycopg2
from psycopg2 import sql
from psycopg2.extensions import ISOLATION_LEVEL_AUTOCOMMIT # <-- ADD THIS LINE

con = psycopg2.connect(dbname='postgres',
      user=self.user_name, host='',
      password=self.password)

con.set_isolation_level(ISOLATION_LEVEL_AUTOCOMMIT) # <-- ADD THIS LINE

cur = con.cursor()

# Use the psycopg2.sql module instead of string concatenation 
# in order to avoid sql injection attacs.
cur.execute(sql.SQL("CREATE DATABASE {}").format(
        sql.Identifier(self.db_name))
    )

As shown in the other answer the connection must be in autocommit mode. Another way of setting it using psycopg2 is through the autocommit attribute:

import psycopg2
from psycopg2 import sql

con = psycopg2.connect(...)
con.autocommit = True

cur = con.cursor()
# sql.SQL and sql.Identifier are needed to avoid SQL injection attacks.
cur.execute(sql.SQL('CREATE DATABASE {};').format(
    sql.Identifier(self.db_name)))