更改Flask 0.12中的默认格式化程序

Question

我正在尝试更改Flask 0.12中的默认格式化程序。这是我的代码

from pomegranate.routes import app
import os

from flask import request
from flask.logging import Formatter, StreamHandler, DEBUG

class RequestFormatter(Formatter):
    def format(self, record):
        record.url = request.url
        record.remote_addr = request.remote_addr
        record.request_id = request.headers.get('X-Request-Id', '')
        return super().format(record)

formatter = RequestFormatter(
    '[%(asctime)s] %(request_id)s %(remote_addr)s %(url)s\n'
    '%(levelname)s %(module)s: %(message)s'
)

stream_handler = StreamHandler()
stream_handler.setLevel(DEBUG)
app.logger.addHandler(stream_handler)
for handler in app.logger.handlers:
    handler.setFormatter(formatter)

dev = int(os.getenv('FLASK_DEBUG', 0))

if __name__ == '__main__':
    host = '0.0.0.0' if dev == 1 else '127.0.0.1'
    app.run(host=host, port=8081, debug=True)

但新的格式化程序似乎没有生效。它仍然使用默认格式化程序。出了什么问题？