title: The input argument `input.value` must be a list or tuple of `dash.dependencies.Input`s. dash
body: <p>i'm trying to learn dash i'm at the <a href="https://dash.plotly.com/basic-callbacks" rel="nofollow noreferrer">third tutorial</a>  but it raise this error whenever i run the file(python app.py)</p>
  <blockquote>
  <p>dash.exceptions.IncorrectTypeException: The input argument <code>input.value</code> must be a list or tuple of <code>dash.dependencies.Input</code>s.</p>
  </blockquote>
  <p>this is the code i'm running :</p>
  <pre><code>import dash
  import dash_core_components as dcc
  import dash_html_components as html
  from dash.dependencies import Input, Output
  
  external_stylesheets = ['https://codepen.io/chriddyp/pen/bWLwgP.css']
  
  app = dash.Dash(__name__, external_stylesheets=external_stylesheets)
  
  app.layout = html.Div([
     html.H6(&quot;Change the value in the text box to see callbacks in action!&quot;),
     html.Div([&quot;Input: &quot;,
            dcc.Input(id='input', value='initial value', type='text')]),
     html.Br(),
     html.Div(id='output'),
  
  ])
  
  
  @app.callback(
      Output(component_id='output', component_property='children'),
      Input(component_id='input', component_property='value')
  )
  def update_output_div(input_value):
      return 'Output: {}'.format(input_value)
  
  
  if __name__ == '__main__':
      app.run_server(debug=True)
  </code></pre>
  <p>please what is wrong with the code?! even i tried to copy and paste the code still raise the same error
  thank you ..</p>
  <p><strong>versions</strong></p>
  <p>python = 3.6</p>
  <p>dash=1.7.0</p>
  <p>dash-core-components=1.6.0</p>
  <p>dash-html-components=1.0.2</p>