PostgreSQL: テーブルの所有者を変更する (Python3)

PostgreSQL で複数のテーブルの所有者を変更する方法です。
Ubuntu 21.10 で確認しました。

ライブラリーのインストール

sudo apt install python3-dotenv

.env

user='******'
password='******'
data_base='******'

change_owner.py

#! /usr/bin/python3
# -*- coding: utf-8 -*-
#
#	change_owner.py
#					Nov/20/2021
#
# --------------------------------------------------------
import os
import sys
import psycopg2
import psycopg2.extras
from dotenv import load_dotenv
#
# --------------------------------------------------------
def display_tables_proc(cursor):
    sql_str="select schemaname, tablename, tableowner from pg_tables where schemaname='public' order by tablename"
    cursor.execute (sql_str)
    rows = cursor.fetchall ()
    for row in rows:
        print(row['tablename'],row['tableowner'])
# 
# --------------------------------------------------------
sys.stderr.write ("*** 開始 ***\n")
dotenv_path = '.env'
load_dotenv(dotenv_path)
USER=os.environ.get("user")
PASSWORD=os.environ.get("user")
DATA_BASE=os.environ.get("data_base")
#
conn = psycopg2.connect("dbname=" + DATA_BASE + " user=" + USER + " password=" + PASSWORD)
cursor = conn.cursor(cursor_factory=psycopg2.extras.DictCursor)
#
sql_str="select schemaname, tablename, tableowner from pg_tables where schemaname='public' order by tablename"
cursor.execute (sql_str)
rows = cursor.fetchall ()
owner_new = "scott" 
for row in rows:
#    print(row)
    print(row['tablename'],row['tableowner'])
    tablename = row['tablename']
    sql_str = "alter table " + tablename + " owner to " + owner_new
    print(sql_str)
    cursor.execute (sql_str)
    conn.commit ()
#
display_tables_proc(cursor)
cursor.close()
conn.close()
#
sys.stderr.write ("*** 終了 ***\n")
#
# --------------------------------------------------------