create_tables.py

import configparser
import psycopg2
from sql_queries import create_table_queries, drop_table_queries


def drop_tables(cur, conn):
    """
    DROP tables just in case before inserting them back again when running the create_tables query
    parameter cur required
    parameter conn requiered
    """
    for query in drop_table_queries:
        cur.execute(query)
        conn.commit()


def create_tables(cur, conn):
    """
    Creates all the tables needed to perform the ETL proccess 
    parameter cur required
    parameter conn requiered
    """
    for query in create_table_queries:
        cur.execute(query)
        conn.commit()


def main():
    config = configparser.ConfigParser()
    config.read('dwh.cfg')

    conn = psycopg2.connect("user={} password={} host={} port={} dbname={}".format(*config['CLUSTER'].values()))
    cur = conn.cursor()

    drop_tables(cur, conn)
    create_tables(cur, conn)

    conn.close()


if __name__ == "__main__":
    main()