Dash unable to read pickle file after deploying on heroku

Hi All,

I have deployed a dash app on Heroku for prediction of car price. But after deployment it is unable to reflect the predicted price.

Below are the example on local

this is on heroku


I am using pickle file for the prediction. Below is the code to create an app

import dash
import dash_bootstrap_components as dbc
from dash.dependencies import Input, Output
from loaded_model import loadmodel
from layout import layout
import pandas as pd
import numpy as np

app = dash.Dash(__name__,external_stylesheets=[dbc.themes.BOOTSTRAP])
server = app.server
app.layout = layout()

@app.callback(Output('priceindicator', 'children'),
              [Input('old_price_range', 'value'),
               Input('new_price_range', 'value'),
               Input('years', 'value'),
               Input('distance_covered', 'value'),
               Input('rating', 'value'),
               Input('condition', 'value'),
               Input('Mileage', 'value'),
               Input('Speed', 'value'),
               Input('Hp', 'value')])
def predict_price(value1,value2,value3,value4,value5,value6,value7,value8,value9):
    model = loadmodel('finalized_model.pkl')
    X_single_point = pd.DataFrame(data = np.array([[value1,value2,value3,value4,int(value5),int(value6),value7,value8,value9]]),
                              columns = ['on road old', 'on road now', 'years', 'km ', 'rating', 'condition', 'economy', 'top speed', 'hp']               
    predicted_price = model.predict(X_single_point)
    return  'Price : {}'.format(int(round(predicted_price[0])))

if __name__ == "__main__":

below to code read pickle file

import pickle

def loadmodel(filename):
    loaded_model = pickle.load(open(filename, 'rb'))
    return loaded_model

Please help me if I miss some steps

Have you uploaded the file to Heroku?

Hi Emil,

Yes, I have uploaded the pickle file and I confirmed it. Also when I downloaded the code from Heroku and ran it locally, it work correctly. I am unable to understand why it is not working on Heroku.

Hi Abhinav,

I have run into the same problem as you have. Pickle is unable to load the module while my web app is running on streamlit, deployed on Heroku. If you have found the fix to the problem, kindly update.