Dash Layout.py

app = dash.Dash()

df = px.data.iris()

app.layout = html.Div([
        html.H1(
            id = 'H1',
            children = 'Styling using html components',
            style = {'textAlign':'center', 'marginTop':40,'marginBottom':40}
        ),

        dcc.Dropdown(
            id = 'dropdown',
            options = [
                {'label':'Setosa', 'value':'setosa' },
                {'label': 'Versicolor', 'value':'versicolor'},
                {'label': 'Virginica', 'value':'virginica'}
            ],
            value = 'setosa'
        ),
    
        dcc.Graph(id = 'graph')
    ])