app.py

import os

import pickle

import warnings

import joblib

import numpy as np

import pandas as pd

import xgboost as xgb

import streamlit as st

import sklearn
from sklearn.metrics import r2_score
from sklearn.ensemble import RandomForestRegressor
from sklearn.metrics.pairwise import rbf_kernel
from sklearn.base import BaseEstimator, TransformerMixin
from sklearn.pipeline import Pipeline, FeatureUnion
from sklearn.compose import ColumnTransformer
from sklearn.impute import SimpleImputer
from sklearn.preprocessing import (
	OneHotEncoder,
	OrdinalEncoder,
	StandardScaler,
	MinMaxScaler,
	PowerTransformer,
	FunctionTransformer
)

from feature_engine.outliers import Winsorizer
from feature_engine.datetime import DatetimeFeatures
from feature_engine.selection import SelectBySingleFeaturePerformance
from feature_engine.encoding import (
	RareLabelEncoder,
	MeanEncoder,
	CountFrequencyEncoder
)

sklearn.set_config(transform_output="pandas")

# convenience functions


# preprocessing operations
air_transformer = Pipeline(steps=[
	("imputer", SimpleImputer(strategy="most_frequent")),
	("grouper", RareLabelEncoder(tol=0.1, replace_with="Other", n_categories=2)),
	("encoder", OneHotEncoder(sparse_output=False, handle_unknown="ignore"))
])

#doj
feature_to_extract = ["month", "week", "day_of_week", "day_of_year"]

doj_transformer = Pipeline(steps=[
	("dt", DatetimeFeatures(features_to_extract=feature_to_extract, yearfirst=True, format="mixed")),
	("scaler", MinMaxScaler())
])

# source & destination
location_pipe1 = Pipeline(steps=[
	("grouper", RareLabelEncoder(tol=0.1, replace_with="Other", n_categories=2)),
	("encoder", MeanEncoder()),
	("scaler", PowerTransformer())
])

def is_north(X):
	columns = X.columns.to_list()
	north_cities = ["Delhi", "Kolkata", "Mumbai", "New Delhi"]
	return (
		X
		.assign(**{
			f"{col}_is_north": X.loc[:, col].isin(north_cities).astype(int)
			for col in columns
		})
		.drop(columns=columns)
	)

location_transformer = FeatureUnion(transformer_list=[
	("part1", location_pipe1),
	("part2", FunctionTransformer(func=is_north))
])

# dep_time & arrival_time
time_pipe1 = Pipeline(steps=[
	("dt", DatetimeFeatures(features_to_extract=["hour", "minute"])),
	("scaler", MinMaxScaler())
])

def part_of_day(X, morning=4, noon=12, eve=16, night=20):
	columns = X.columns.to_list()
	X_temp = X.assign(**{
		col: pd.to_datetime(X.loc[:, col]).dt.hour
		for col in columns
	})

	return (
		X_temp
		.assign(**{
			f"{col}_part_of_day": np.select(
				[X_temp.loc[:, col].between(morning, noon, inclusive="left"),
				 X_temp.loc[:, col].between(noon, eve, inclusive="left"),
				 X_temp.loc[:, col].between(eve, night, inclusive="left")],
				["morning", "afternoon", "evening"],
				default="night"
			)
			for col in columns
		})
		.drop(columns=columns)
	)

time_pipe2 = Pipeline(steps=[
	("part", FunctionTransformer(func=part_of_day)),
	("encoder", CountFrequencyEncoder()),
	("scaler", MinMaxScaler())
])

time_transformer = FeatureUnion(transformer_list=[
	("part1", time_pipe1),
	("part2", time_pipe2)
])

# duration
class RBFPercentileSimilarity(BaseEstimator, TransformerMixin):
	def __init__(self, variables=None, percentiles=[0.25, 0.5, 0.75], gamma=0.1):
		self.variables = variables
		self.percentiles = percentiles
		self.gamma = gamma


	def fit(self, X, y=None):
		if not self.variables:
			self.variables = X.select_dtypes(include="number").columns.to_list()

		self.reference_values_ = {
			col: (
				X
				.loc[:, col]
				.quantile(self.percentiles)
				.values
				.reshape(-1, 1)
			)
			for col in self.variables
		}

		return self


	def transform(self, X):
		objects = []
		for col in self.variables:
			columns = [f"{col}_rbf_{int(percentile * 100)}" for percentile in self.percentiles]
			obj = pd.DataFrame(
				data=rbf_kernel(X.loc[:, [col]], Y=self.reference_values_[col], gamma=self.gamma),
				columns=columns
			)
			objects.append(obj)
		return pd.concat(objects, axis=1)
	

def duration_category(X, short=180, med=400):
	return (
		X
		.assign(duration_cat=np.select([X.duration.lt(short),
										X.duration.between(short, med, inclusive="left")],
									   ["short", "medium"],
									   default="long"))
		.drop(columns="duration")
	)

def is_over(X, value=1000):
	return (
		X
		.assign(**{
			f"duration_over_{value}": X.duration.ge(value).astype(int)
		})
		.drop(columns="duration")
	)

duration_pipe1 = Pipeline(steps=[
	("rbf", RBFPercentileSimilarity()),
	("scaler", PowerTransformer())
])

duration_pipe2 = Pipeline(steps=[
	("cat", FunctionTransformer(func=duration_category)),
	("encoder", OrdinalEncoder(categories=[["short", "medium", "long"]]))
])

duration_union = FeatureUnion(transformer_list=[
	("part1", duration_pipe1),
	("part2", duration_pipe2),
	("part3", FunctionTransformer(func=is_over)),
	("part4", StandardScaler())
])

duration_transformer = Pipeline(steps=[
	("outliers", Winsorizer(capping_method="iqr", fold=1.5)),
	("imputer", SimpleImputer(strategy="median")),
	("union", duration_union)
])

# total_stops
def is_direct(X):
	return X.assign(is_direct_flight=X.total_stops.eq(0).astype(int))


total_stops_transformer = Pipeline(steps=[
	("imputer", SimpleImputer(strategy="most_frequent")),
	("", FunctionTransformer(func=is_direct))
])

# additional_info
info_pipe1 = Pipeline(steps=[
	("group", RareLabelEncoder(tol=0.1, n_categories=2, replace_with="Other")),
	("encoder", OneHotEncoder(handle_unknown="ignore", sparse_output=False))
])

def have_info(X):
	return X.assign(additional_info=X.additional_info.ne("No Info").astype(int))

info_union = FeatureUnion(transformer_list=[
	("part1", info_pipe1),
	("part2", FunctionTransformer(func=have_info))
])

info_transformer = Pipeline(steps=[
	("imputer", SimpleImputer(strategy="constant", fill_value="unknown")),
	("union", info_union)
])

# column transformer
column_transformer = ColumnTransformer(transformers=[
	("air", air_transformer, ["airline"]),
	("doj", doj_transformer, ["date_of_journey"]),
	("location", location_transformer, ["source", 'destination']),
	("time", time_transformer, ["dep_time", "arrival_time"]),
	("dur", duration_transformer, ["duration"]),
	("stops", total_stops_transformer, ["total_stops"]),
	("info", info_transformer, ["additional_info"])
], remainder="passthrough")

# feature selector
estimator = RandomForestRegressor(n_estimators=10, max_depth=3, random_state=42)

selector = SelectBySingleFeaturePerformance(
	estimator=estimator,
	scoring="r2",
	threshold=0.1
) 

# preprocessor
preprocessor = Pipeline(steps=[
	("ct", column_transformer),
	("selector", selector)
])

# read the training data
train = pd.read_csv("train.csv")
X_train = train.drop(columns="price")
y_train = train.price.copy()

# fit and save the preprocessor
preprocessor.fit(X_train, y_train)

joblib.dump(preprocessor, "preprocessor.joblib")

# web application
st.set_page_config(
	page_title="Flights Prices Prediction",
	page_icon="✈️",
	layout="wide"
)
st.title("Flights Prices Prediction - AWS SageMaker")

# user inputs
airline = st.selectbox(
	"Airline:",
	options=X_train.airline.unique()
)

doj = st.date_input("Date of Journey:")

source = st.selectbox(
	"Source",
	options=X_train.source.unique()
)

destination = st.selectbox(
	"Destination",
	options=X_train.destination.unique()
)

dep_time = st.time_input("Departure Time:")

arrival_time = st.time_input("Arrival Time:")

duration = st.number_input(
	"Duration (mins):",
	step=1
)

total_stops = st.number_input(
	"Total Stops:",
	step=1,
	min_value=0
)

additional_info = st.selectbox(
	"Additional Info:",
	options=X_train.additional_info.unique()
)

x_new = pd.DataFrame(dict(
	airline=[airline],
	date_of_journey=[doj],
	source=[source],
	destination=[destination],
	dep_time=[dep_time],
	arrival_time=[arrival_time],
	duration=[duration],
	total_stops=[total_stops],
	additional_info=[additional_info]
)).astype({
	col: "str"
	for col in ["date_of_journey", "dep_time", "arrival_time"]
})

if st.button("Predict"):
	saved_preprocessor = joblib.load("preprocessor.joblib")
	x_new_pre = saved_preprocessor.transform(x_new)

	with open("XGB-model", "rb") as f:
		model = pickle.load(f)
	x_new_xgb = xgb.DMatrix(x_new_pre)
	pred = model.get_booster().predict(x_new_xgb)[0]

	st.info(f"The predicted price is {pred:,.0f} INR")
st.markdown("""
    <div class="footer">
    <p>Made by- ✈️Debasish Das🌍</p>
    </div>
""", unsafe_allow_html=True)