Plotly-Dash:隐藏和取消隐藏下拉菜单

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

app = dash.Dash(__name__)

app.layout = html.Div([
    dcc.Dropdown(
        id='dropdown',
        options=[
            {'label': 'Option 1', 'value': 'option1'},
            {'label': 'Option 2', 'value': 'option2'},
            {'label': 'Option 3', 'value': 'option3'}
        ],
        value='option1'
    ),
    html.Div(id='output')
])

@app.callback(
    Output('dropdown', 'style'),
    [Input('dropdown', 'value')]
)
def hide_dropdown(value):
    if value == 'option1':
        return {'display': 'none'}
    else:
        return {'display': 'block'}

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