Plotly-Dash:根据选定的df列添加新的yaxis

import dash
import dash_core_components as dcc
import dash_html_components as html
from dash.dependencies import Input, Output
import plotly.graph_objs as go

app = dash.Dash(__name__)

app.layout = html.Div([
    dcc.Dropdown(
        id='column-dropdown',
        options=[{'label': col, 'value': col} for col in df.columns],
        value=df.columns[0]
    ),
    dcc.Graph(id='graph')
])

@app.callback(
    Output('graph', 'figure'),
    [Input('column-dropdown', 'value')]
)
def update_graph(selected_column):
    data = [
        go.Scatter(
            x=df.index,
            y=df[selected_column],
            mode='lines',
            name=selected_column
        )
    ]
    layout = go.Layout(
        yaxis=dict(
            title=selected_column
        ),
        yaxis2=dict(
            title='New Y-axis'
        ),
        title='Plotly-Dash Example'
    )
    fig = go.Figure(data=data, layout=layout)
    fig['layout']['yaxis2'] = dict(
        overlaying='y',
        side='right'
    )
    return fig

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