使用bottle_flash2实现Bottle flash消息时报错AttributeError问题咨询

因无法安装bottle_flash组件，当前使用bottle_flash2作为替代。代码完全参照该项目PyPI页面的示例编写，除了在routes.py中新增了程序启动的主函数外，其余内容与示例完全一致，但运行时一直报错AttributeError: 'str' object has no attribute 'append'，未检索到同类问题的公开讨论，不清楚解决方向。

测试代码 #

routes.py #

from bottle import Bottle, post, jinja2_template as template,run
from bottle_flash2 import FlashPlugin

# Flash Setup
app = Bottle()
COOKIE_SECRET = 'super_secret_string'
app.install(FlashPlugin(secret=COOKIE_SECRET))

@app.route('/flash_sample_done')
def flash_sample():
    app.flash("flash message is here")

    # flash mesage is stored in list
    # Therefore, it is possible to store a multiple messages.
    app.flash("flash message 1")
    app.flash("flash message 2")

    return template('index.html', app = app)



if __name__ == "__main__":

    run(app, host='localhost', port=8080, debug=True)

index.html #

% messages = app.get_flashed_messages()
% if messages:
<div id=flash_messages>
<ul>
% for m in messages
<li>{{ m[0] }}</li>
% endfor
</ul>
</div>
% endif

完整报错追踪栈 #

Traceback (most recent call last):
  File "C:\Users\user\AppData\Local\Programs\Python\Python39\lib\site-packages\bottle.py", line 868, in _handle
    return route.call(**args)
  File "C:\Users\user\AppData\Local\Programs\Python\Python39\lib\site-packages\bottle.py", line 1748, in wrapper
    rv = callback(*a, **ka)
  File "C:\Users\user\Desktop\temp\test\routes.py", line 11, in flash_sample
    app.flash("flash message is here")
  File "C:\Users\user\AppData\Local\Programs\Python\Python39\lib\site-packages\bottle_flash2.py", line 32, in flash
    response.flash_messages.append((message, level))
AttributeError: 'str' object has no attribute 'append'

内容的提问来源于stack exchange，提问作者SadSalad