如何在Flask中打开和处理.rtf文件

from flask import Flask, request, send_file
import os

app = Flask(__name__)

@app.route('/upload', methods=['POST'])
def upload_file():
    file = request.files['file']
    if file and allowed_file(file.filename):
        filename = secure_filename(file.filename)
        file.save(os.path.join(app.config['UPLOAD_FOLDER'], filename))
        return '文件上传成功'
    else:
        return '不支持的文件格式'

def allowed_file(filename):
    return '.' in filename and filename.rsplit('.', 1)[1].lower() == 'rtf'

@app.route('/download/<filename>', methods=['GET'])
def download_file(filename):
    return send_file(os.path.join(app.config['UPLOAD_FOLDER'], filename), as_attachment=True)

if __name__ == '__main__':
    app.config['UPLOAD_FOLDER'] = 'uploads'  # 设置文件上传保存的目录
    app.run()