Plotly Dash 错误加载布局

Question

您好，我是 Dash 的新手，我正在关注页面 https://dash.plot.ly/getting-started 上的教程，我收到一个错误，指出未安装 msgpack。我稍后安装它，然后运行页面上给出的以下代码。

import dash
import dash_core_components as dcc
import dash_html_components as html

app = dash.Dash()

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':[2,4,1],'type':'bar','name':'SF'}
            ],
            'layout': {
                'title':'Dash Data Visualisation'
            }
        }
    )
])

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

当我继续 http://127.0.0.1:8050/ 时，我收到以下错误

Error loading layout

我阅读了 dash 文档和社区帮助，有人问了一些类似的问题，但我无法理解它们。请帮忙。

Answer 1

code 在终端中运行时运行良好。该链接显示bar plot（如下）。可能是您的dash 安装缺少一些libraries / requirement 文件。您可以尝试从终端执行pip install 或conda install 下面列出的pacakges。

使用pip安装的示例

$ pip install <package name here>

或者如果使用Ananconda

$ conda install <package name here>

示例：

$ pip install chardet==3.0.4

包

chardet==3.0.4
click==6.7
Cython==0.28.2
dash==0.21.0
dash-core-components==0.22.1
dash-html-components==0.10.0
dash-renderer==0.12.1
decorator==4.3.0
nbformat==4.4.0
numpy==1.14.2
pandas==0.22.0
pandas-datareader==0.6.0
plotly==2.5.1
python-dateutil==2.7.2
pytz==2018.4
requests==2.18.4
urllib3==1.22
Werkzeug==0.14.1

编辑 - 1 .........................................

import dash
import dash_core_components as dcc
import dash_html_components as html

app = dash.Dash()
app.layout = html.Div(children=[html.H1(children='Hello Dash')])
if __name__ == '__main__':
    app.run_server(debug=True)

在post的基础上添加下面一行来导入。

import dash
import dash_core_components as dcc
import dash_html_components as html
from dashapp import app as application

app = dash.Dash()
app.layout = html.Div(children=[html.H1(children='Hello Dash')])
if __name__ == '__main__':
    app.run_server(debug=True)

或

import dash
import dash_core_components as dcc
import dash_html_components as html
from dashapp import server as application

app = dash.Dash()
app.layout = html.Div(children=[html.H1(children='Hello Dash')])
if __name__ == '__main__':
    app.run_server(debug=True)

或

import dash
import dash_core_components as dcc
import dash_html_components as html
from dashapp import server as application

app = dash.Dash()
app.layout = html.Div(children=[html.H1(children='Hello Dash')])
if __name__ == '__main__':
    app.run_server(debug=True)

from dashapp import server as application

和/或更改以下任一 [post]：

app = Dash()
app = dash.Dash(__name__)
server = app.server

编辑 - 2 .........................................

Install dash libraries

pip install dash==0.21.1  # The core dash backend
pip install dash-renderer==0.13.0  # The dash front-end
pip install dash-html-components==0.11.0  # HTML components
pip install dash-core-components==0.24.0  # Supercharged components
pip install plotly --upgrade  # Latest Plotly graphing library

和also

pip install dash.ly --upgrade

Answer 2

我再次删除了所有库并重新安装了它们，并在 Chrome 中运行了代码。现在工作正常。

Answer 3

我也是 Dash 的新手，就我而言，语法有问题。

我正在这样做：

app.layout = html.Div({

并且收到“错误加载布局”

但是当我切换到这个时：

app.layout = html.Div(children=[

错误消失了。

检查主 Div 的语法是否有任何错误。

Answer 4

当您在较旧的 Shinyproxy 版本中使用 dash 时，您会遇到同样的错误。由于搜索会将您重定向到此帖子，因此我也将答案放在这里。

使用

app.config.update({
'routes_pathname_prefix': os.environ['SHINYPROXY_PUBLIC_PATH'],
'requests_pathname_prefix': os.environ['SHINYPROXY_PUBLIC_PATH']
})

如图here和讨论here