Dropdown is not working - Returning Empty graph

stage_options = []
for Stage in df[‘Stage’].unique():
stage_options.append({‘label’:str(Stage), ‘value’:Stage})

year_options = []
for year in df[‘year’].unique():
year_options.append({‘label’:str(year),‘value’:year})

app.layout = html.Div(children = [html.H1([‘P 61’]),
dcc.Dropdown(id = ‘Stage’, options = stage_options, value = df[‘Stage’]),
dcc.Dropdown(id = ‘dd’, options = [{‘value’:w,‘label’:w} for w in words],value =df[‘year’]),
dcc.Dropdown(id = ‘year-picker’, options = year_options, value =‘year’),
dcc.Graph(id=‘graph’)])

@app.callback(dash.dependencies.Output(‘graph’,‘figure’),
[dash.dependencies.Input(‘dd’,‘value’),
dash.dependencies.Input(‘year-picker’,‘value’),
dash.dependencies.Input(‘Stage’,‘value’),
]
)

def update_figure(value,selected_year,Stage):
df_year = df.loc[df[‘year’] == selected_year]
df_year = df.loc[df[‘Stage’] == Stage]
df_year = df[df[‘Activity Name’].str.contains(value)]

for Activity_Type in df_year['Activity Type'].unique():
    df_at= df_year.loc[df_year['Activity Type'] == 'Finish Milestone']