dash problems

[zhujp98]

I want to scatter plot campcnt vs cnt by year, but I get error msg. How to fix this problem?
Thanks,
Jeff

print(df.head())


app = dash.Dash()
app.layout = html.Div([
    dcc.Graph(
        id='life-exp-vs-gdp',
        figure={
            'data': [
                go.Scatter(
                    x=df[df['year'] == i]['cntcamp'],
                    y=df[df['year'] == i]['cnt'],
                    mode='markers',
                    opacity=0.7,
                    marker={
                        'size': 15,
                        'line': {'width': 0.5, 'color': 'white'}
                    },
                    name=i
                ) for i in df.year.unique()
            ],
            'layout': go.Layout(
                xaxis={'type': 'log', 'title': 'Camp Count'},
                yaxis={'title': 'Total count'},
                margin={'l': 40, 'b': 40, 't': 10, 'r': 10},
                legend={'x': 0, 'y': 1},
                hovermode='closest'
            )
        }
    )
])

Output:
   year  cntcamp        cnt
0  2015       36  347318781
1  2017      100  115586825
2  2016       48   59420381
3  2018       49   12924098
4  2014        6    2052933

Error:
Traceback (most recent call last):

  File "<ipython-input-8-ddb45a8148ad>", line 20, in <module>
    ) for i in df.year.unique()

AttributeError: 'SASdata' object has no attribute 'year'