old_contents: import os
  
  import peewee
  
  APP_DIR = os.path.dirname(__file__)
  
  try:
      import urlparse
      import psycopg2
      urlparse.uses_netloc.append('postgres')
      url = urlparse.urlparse(os.environ["DATABASE_URL"])
      database = peewee.PostgresqlDatabase(database=url.path[1:],
                                           user=url.username,
                                           password=url.password,
                                           host=url.hostname,
                                           port=url.port)
  except KeyError:
      database = peewee.MySQLDatabase(os.environ["MYSQL_DATABASE"],
                                      os.environ["MYSQL_HOST"],
                                      user=os.environ["MYSQL_USER"],
                                      passwd=os.environ["MYSQL_PASSWD"])
  
new_contents: import os
  
  import peewee
  
  APP_DIR = os.path.dirname(__file__)
  
  try:
      import urlparse
      import psycopg2
      urlparse.uses_netloc.append('postgres')
      url = urlparse.urlparse(os.environ["DATABASE_URL"])
      database = peewee.PostgresqlDatabase(database=url.path[1:],
                                           user=url.username,
                                           password=url.password,
                                           host=url.hostname,
                                           port=url.port)
  except KeyError:
      database = peewee.SqliteDatabase('my_app.db')
  
subject: Change from MySQL to SQLite3