import csv
import xlrd
import os
import psycopg2
import django
from simplemostmeals import settings
django.setup()
from core import models


try:
    conn = psycopg2.connect("host=localhost dbname=prodmealsdb user=postgres password=blank")
    cur = conn.cursor()

    filepath = '/path/to/your/data_to_be_updated.csv'
    ext = os.path.splitext(filepath)[-1].lower()
    if (ext == '.csv'):
        print("csv file")
        with open(filepath) as csvfile:
            next(csvfile)
            readCSV = csv.reader(csvfile, delimiter=',')
            for row in readCSV:
                print(row[3],row[5])
                cur.execute("UPDATE your_table SET column_to_be_updated = %s where id = %s", (row[5], row[3]))
                conn.commit()
            conn.close()
            cur.close()

except (Exception, psycopg2.DatabaseError) as error:
        print(error)
finally:
 if conn is not None:
   conn.close()