Python dash gauge -如何使用字符串作为值而不是数字？

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.Input(id='input', value='Normal', type='text'),
    dcc.Gauge(
        id='gauge',
        value=0,
        min=0,
        max=100,
        label='Gauge',
        showCurrentValue=True,
        number={'suffix': ' %'}
    )
])

@app.callback(
    Output('gauge', 'value'),
    [Input('input', 'value')]
)
def update_gauge(value):
    return value

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