app.py

from flask import Flask, render_template, request, jsonify
import os
import numpy as np
import yaml
import joblib

webapp_root = 'webapp'
params_path = 'params.yaml'

static_dir = os.path.join(webapp_root, 'static')
template_dir = os.path.join(webapp_root, 'templates')

app = Flask(__name__, 
            static_folder=static_dir, 
            template_folder=template_dir)

class NotANumber(Exception):
    def __init__(self, message = "Values entered are not Numerical"):
        self.message = message
        super().__init__(self.message)

def read_params(config_path):
    with open(config_path, 'r') as yaml_file:
        config = yaml.safe_load(yaml_file)
    return config

def predict(data):
    config = read_params(params_path)
    model_dir_path = config['model_webapp_dir']
    model = joblib.load(model_dir_path)
    prediction = model.predict(data).tolist()[0]
    return prediction


def validate_input(dict_request):
    for _, val in dict_request.items():
        try:
            val = float(val)
        except Exception as e:
            raise NotANumber

    return True

def form_response(dict_request):
    try:
        if validate_input(dict_request):
            data = dict_request.values()
            data = [list(map(float, data))]
            response = predict(data)
            return response
    except NotANumber as e:
        response = str(e)
        return response

@app.route('/', methods=['GET', 'POST'])
def index():
    if request.method == 'POST':
        try:
            if request.form:
                dict_req = dict(request.form)
                response = form_response(dict_req)
                return render_template('index.html', response=response)
        except Exception as e:
            print(e)
            error = {"error": "something went wrong!! Try again later!"}
            error = {"error": e}
            return render_template('404.html', error=error)
    else:
        return render_template('index.html')


if __name__ == '__main__':
    app.run(host='0.0.0.0', port = 1991, debug=True)