Google Colab-Plotly Dash-示例破折号应用程序停留在产品环境中

Question

该代码正在运行，但希望在/ prod文件夹中查找它是否在生产环境中。

这是我的笔记本：https://colab.research.google.com/drive/1bvrH80Apj3HVI3TQ2U9H87ANhnCrVahH

这是我使用NGROK.IO的简单代码

  # How to run a Dash app in Google Colab

  ## Requirements

  ### Install ngrok
  !wget https://bin.equinox.io/c/4VmDzA7iaHb/ngrok-stable-linux-amd64.zip
  !unzip ngrok-stable-linux-amd64.zip

  ### Run ngrok to tunnel Dash app port 8050 to the outside world. 
  ### This command runs in the background.
  get_ipython().system_raw('./ngrok http 8050 &')

  ### Get the public URL where you can access the Dash app. Copy this URL.
  ! curl -s http://localhost:4040/api/tunnels | python3 -c \
      "import sys, json; print(json.load(sys.stdin)['tunnels'][0]['public_url'])"

  ### Install Dash
  !pip install dash==0.31.1  # The core dash backend
  !pip install dash-html-components==0.13.2  # HTML components
  !pip install dash-core-components==0.39.0  # Supercharged components
  !pip install dash-table==3.1.7  # Interactive DataTable component (new!)

。

  ## Dash app (https://dash.plot.ly/getting-started)

  ### Save file with Dash app on the Google Colab machine
  %%writefile my_app1.py
  import dash
  import dash_core_components as dcc
  import dash_html_components as html

  external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css']

  app = dash.Dash(__name__, external_stylesheets=external_stylesheets)

  app.layout = html.Div(children=[
      html.H1(children='Hello Dash'),

      html.Div(children='''
          Dash: A web application framework for Python.
      '''),

      dcc.Graph(
          id='example-graph',
          figure={
              'data': [
                  {'x': [1, 2, 3], 'y': [4, 1, 2], 'type': 'bar', 'name': 'SF'},
                  {'x': [1, 2, 3], 'y': [2, 4, 5], 'type': 'bar', 'name': u'Montréal'},
              ],
              'layout': {
                  'title': 'Dash Data Visualization'
              }
          }
      )
  ])

  if __name__ == '__main__':
      app.run_server(debug=True)

。

  ### Run Dash app
  import os
  os.environ['FLASK_ENV'] = 'development'
  !python my_app1.py

这是我得到的错误：