Choropleth地图的Dash应用程序回调

Question

我有一些问题，回调函数在巧妙的破折号。我希望我的合唱地图能根据选定的年份更新。滑块本身工作，并选择正确的数据(使用"print(filtered_df)“语句检查)。然而，地图并没有相应地更新，我只是不明白为什么。我遗漏了什么？

谢谢你的帮助！

app = dash.Dash(__name__, external_stylesheets=[dbc.themes.FLATLY])

app.layout = dbc.Container(html.Div([

    dbc.Row(
        [
            dcc.Graph(id='graph-with-slider'),
            dcc.Slider(
                min=df['year'].min(),
                max=df['year'].max(),
                step=None,
                value=df['year'].max(),
                marks={str(year): str(year) for year in df['year'].unique()},
                id='year-slider'
            )
        ]
    )
]))


@app.callback(
    Output(component_id='graph-with-slider', component_property='figure'),
    [Input(component_id='year-slider', component_property='value')]
)
def update_figure(selected_year):
    filtered_df = df.loc[df.year == selected_year].reset_index()
    #print(filtered_df)

    fig = px.choropleth(filtered_df, locations=df['Country Code'], locationmode='ISO-3',
                        color=df['life_expectancy_total'], color_continuous_scale=colorscale)
    fig.update_layout(transition_duration=500)
    return fig

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

Answer 1

..。发现问题了！我只是没有在代码的这一部分调用正确的df :/

fig = px.choropleth(filtered_df, locations=df['Country Code'], locationmode='ISO-3', color=df['life_expectancy_total'], color_continuous_scale=colorscale)

应该是：

fig = px.choropleth(filtered_df, locations=filtered_df['Country Code'], locationmode='ISO-3', color=filtered_df.life_expectancy_avg, color_continuous_scale=colorscale)