带有女服务员的Python Dash服务器

Question

我有一个用Dash框架编写的仪表板应用程序。它还有一些使用flask编写的Restful API。我正在将flask应用程序添加到Dash服务器，因为

import dash
import flask
import dash_bootstrap_components as dbc

flask_server = flask.Flask(__name__)
app = dash.Dash(__name__,server=flask_server, external_stylesheets=[dbc.themes.BOOTSTRAP])

并以如下方式运行服务器：

from dashboard import app
from waitress import serve

if __name__ == "__main__":
    app.title = 'Litmus'
    app.run_server(debug=False)
    # serve(app,host="0.0.0.0",port=8050)

当我使用app.run_server(debug=False)时，上面的代码运行得很好，但是当我使用waitress运行服务器时，它抛出了excetion。当我使用以下几行代码时

#app.run_server(debug=False)
serve(app,host="0.0.0.0",port=8050)

我得到以下错误

ERROR:waitress:Exception while serving /
Traceback (most recent call last):
  File "C:\Users\litmus\AppData\Roaming\Python\Python38\site-packages\waitress\channel.py", line 397, in service
    task.service()
  File "C:\Users\litmus\AppData\Roaming\Python\Python38\site-packages\waitress\task.py", line 168, in service
    self.execute()
  File "C:\Users\litmus\AppData\Roaming\Python\Python38\site-packages\waitress\task.py", line 434, in execute
    app_iter = self.channel.server.application(environ, start_response)
TypeError: 'Dash' object is not callable
ERROR:waitress:Exception while serving /favicon.ico
Traceback (most recent call last):
  File "C:\Users\litmus\AppData\Roaming\Python\Python38\site-packages\waitress\channel.py", line 397, in service
    task.service()
  File "C:\Users\litmus\AppData\Roaming\Python\Python38\site-packages\waitress\task.py", line 168, in service
    self.execute()
  File "C:\Users\litmus\AppData\Roaming\Python\Python38\site-packages\waitress\task.py", line 434, in execute
    app_iter = self.channel.server.application(environ, start_response)
TypeError: 'Dash' object is not callable

Answer 1

它不起作用是因为你将Dash应用程序而不是Flask应用程序传递给了serve。

因此，不是这样：

serve(app,host="0.0.0.0",port=8050)

按如下方式传递Flask应用程序实例：

serve(app.server, host="0.0.0.0", port=8050)