import psycopg2
conn = psycopg2.connect(dbname='postgres', user='sa', 
                        password='qwerty5157', host='localhost')
cursor = conn.cursor()
cursor.execute('SELECT * FROM new LIMIT 10')
for row in cursor:
    print(row)
    

 class User(models.Model):
    dlina_User = models.DecimalField('Длина', max_digits=10, decimal_places=2, null=True, help_text='Длина пользователя’,
                                       validators=[
                                           MinValueValidator(0)
                                       ])