use csv file and plot data django2

Question

I have a simple app that import csv file and make plot but without having any error message it doesn't show plot
It's part of my module:

...
def plot_data(self):
    df = pd.read_csv("file.csv")
    return plotly.express.line(df)
...

and it's part of my app file:

import panel
def app(doc):
   gspec = pn.GridSpec()
   gspec[0, 1] = pn.Pane(instance_class.plot_data())
   gspec.server_doc(doc)

Update:

After searching more I could find HttpResponse and with that I could write things to csv through using csv module but still I have no idea how to read from csv

Also I saw HttpRequest and thought maybe I can use it for reading csv but I couldn't find any sample code and couldn't understand documentation about using it as a reader