centris-property-checker.py

'''

>centris-property-checker.py<
@Author: Maxwell Mowbray
@Email: mmowbray@mentlegen.com
@Date: February 2021
@Description:

This script will periodically check a Centris personal link for new properties.
When a new property appears, the user is notified with a popup.
It can easily be adapted to do other things with the results.
A custom filter can also be defined, to only show popups of properties with certain parameters.

Usage:

1- Download the Chrome web driver from https://chromedriver.chromium.org/downloads and set its location on the disk in APP_SETTINGS
2- Add your personal Centris link below (APP_SETTINGS object) and run.
3- pip install bs4 selenium lxml tkinter

'''

import time
import re

from datetime import datetime

from bs4 import BeautifulSoup
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from selenium.common.exceptions import TimeoutException
from selenium.webdriver.chrome.options import Options
from selenium.webdriver.common.by import By
from selenium import webdriver
import tkinter
from tkinter import messagebox

html = None

APP_SETTINGS = {
    'centris_link': '',
    'selenium_chrome_driver_location': './chromedriver',  # https://chromedriver.chromium.org/downloads
    'check_timeout_seconds': 300,  # 5 minutes
    'property_filter': lambda prop: prop['price'] < 400000 #lambda function that can filter results before alerting
}

results_container_selector = '#_ctl0_m_divAsyncPagedDisplays'

delay = 20

# setup browser (headless)

print(datetime.now().strftime("%H:%M:%S") + " Searching Centris now.")
browser_options = Options()
browser_options.headless = True
browser = webdriver.Chrome(APP_SETTINGS['selenium_chrome_driver_location'], options=browser_options)

property_title_selector = 'div.d-wrapperTable>div.row>div.col-lg-7.col-md-6.col-sm-12>div.row>div.col-xs-12.col-sm-12>span'
property_price_selector = 'div.d-wrapperTable>div.row>div.col-lg-7.col-md-6.col-sm-12>div.row>div.col-xs-9.col-sm-8.col-md-8.col-lg-8>span'

listing_cache = {}
first_check = True

# hide main window
tkinter.Tk().withdraw()

while True:
    try:
        browser.get(APP_SETTINGS['centris_link'])

        # wait for results to be displayed
        WebDriverWait(browser, delay).until(EC.presence_of_element_located((By.CSS_SELECTOR, results_container_selector)))

    except TimeoutException:
        print('Loading took too much time!')
    else:
        html = browser.page_source
        soup = BeautifulSoup(html, 'lxml')

        for property_html in soup.select(results_container_selector)[0].findChildren('div', recursive=False):

            property_result = {}

            property_identifier = property_html.select_one(property_title_selector).text
            property_result['price'] = int(re.sub('[^0-9]', '', property_html.select_one(property_price_selector).text))

            if not property_identifier in listing_cache:
                #first time seeing this property
                listing_cache[property_identifier] = property_result

                if not first_check and APP_SETTINGS['property_filter'](property_result):

                    #alert for a new property
                    print(datetime.now().strftime("%H:%M:%S") + " New property found: " + property_identifier)
                    # messagebox.showinfo("New property found!", "There is a new property: " + property_identifier)

        first_check = False
        time.sleep(APP_SETTINGS['check_timeout_seconds'])