无法读取未定义的虚线数据表的属性'fantasy-land/map' 使用下拉列表更新表

Question

我引用了@chriddyp https://community.plot.ly/t/dash-datatable-updating-rows-with-dropdowns/6714 在此处发布的示例代码片段以及链接帖子上发生的讨论

可重现的示例

import flask
import dash
import dash_core_components as dcc
import dash_html_components as html
import dash_table_experiments as dt
import pandas as pd
from dash.dependencies import Input, Output, State

def create_dropdown_list(df, column):
dd = df.loc[:, [column]].drop_duplicates().reset_index(drop=True)
dd['label'] = dd[column]
dd = dd.rename(columns={column:'value'}).to_dict(orient='records')
return dd

city_temp = pd.DataFrame({'City':['Montreal','New York','San Francisco'], 
'Temperature':[68,83,66]})

server = flask.Flask(__name__)
app = dash.Dash(server=server, )
dropdown_list = create_dropdown_list(city_temp, 'City')
app.layout = html.Div([
dcc.Dropdown(
id='my-dropdown',
options=dropdown_list, # which looks like [{'label': 'Montreal', 'value': 'Montreal'}, {'label': 'New York', 'value': 'New York'}, {'label': 'San Francisco', 'value': 'San Francisco'}]
value = 'Montreal'
),
html.H4(children='My table'),
dt.DataTable(id='my-datatable')
])

@app.callback(Output('my-datatable', 'rows'), [Input('my-dropdown', 'value')])
def update_rows(selected_value):
city_temp_sub = city_temp[city_temp.City == selected_value].reset_index(drop=True)
return city_temp_sub.to_dict('records')
app.css.append_css({
'external_url': 'https://codepen.io/chriddyp/pen/bWLwgP.css'
})
if __name__ == "__main__":
app.run_server()

我在浏览器上收到"加载依赖项时出错" 在控制台上，我收到错误为"类型错误：无法读取未定义的属性'幻想土地/地图'

有人可以帮忙吗？

谢谢

阿努吉

Answer 1

简答

达世币的数据表需要用空rows初始化才能正常工作。

dt.DataTable(id='my-datatable', rows=[{}])

长答案

将代码减少到最低限度有助于发现问题。

import flask
import dash
import dash_html_components as html
import dash_table_experiments as dt
server = flask.Flask(__name__)
app = dash.Dash(server=server, )
app.layout = html.Div([
dt.DataTable(id='my-datatable', rows=[{}])
])
if __name__ == "__main__":
app.run_server()

底层问题隐藏在源代码中： https://github.com/plotly/dash-table-experiments/blob/1e5b24eec53627418c51027f561cb7bae591a95e/dash_table_experiments/metadata.json

参数rows既不required，也没有默认值。

"rows": {
"type": {
"name": "arrayOf",
"value": {
"name": "custom",
"raw": "PropTypes.shape"
}
},
"required": false,
"description": ""
},