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Sharing a table value as a link in the multi page application

I created a data frame and displayed as a table with one column as a Link. I want to share the value on another page. After a few minutes of thinking I came up with an idea which I don’t think it is the right way to do that. I created a link as a request GET method like for example http://127.0.0.1/apps/app2=123456. Where 123456 is a Unique ID and I want to do the analytics to that particular id. So in index.py file I wrote this code

app.layout = html.Div([
    dcc.Location(id='url', refresh=False),
    html.Div(id='page-content', style={'width':'100%'}),
    #this div element is Hidden
    html.Div(id='user-id', style={'display':'none'})

], style={'width':'100%', 'margin-left':'0%'})

@app.callback(Output('page-content', 'children'),
              [Input('url', 'pathname')])

def display_page(pathname):
    #check if pathname carries any uniqueId to review
    separate_uid = pathname
    print("URL PAGE:{}".format(separate_uid))

    if pathname == '/apps/app1':
         return app1.layout

    elif pathname == '/apps/app2':
        return app2.layout

    elif '=' in separate_uid:
        return app3.layout

    else:
        return index.layout

@app.callback(Output('user-id', 'children'),
    [Input('url', 'pathname')])

def get_user_id(pathname):
    #check if pathname carries any uniqueId to review
    separate_uid = pathname

    if '=' in separate_uid:
        uid = separate_uid.split('=')[1]
        return uid

and app3.py file I wrote

layout = html.Div(id='id')

@app.callback(Output('id', 'children'),
           [Input('user-id', 'children')]

def analytics(id):
      return "Select Id is:{}".format(id)

Somehow this is how I managed to pass the table cell value(as a link) to another page. Is there any other way than doing this? Because when I run the index.py file it throwing me an error, but the function is doing its job. The error is in elif '=' in pathname. I make the cell value as a link by this method dcc.Link(value, href='/apps/app3={}'.format(value).

The error is
Type Error: NoneType is not Iteratable. Can somebody help me why this is showing error? and How can I get rid of this error