website_blocker1.pyw

import time
from datetime import datetime as dt

host_temp=r"E:\Rahul\Projects\Python Projects\Website Blocker Application\hosts"
host_path= r"C:\Windows\System32\drivers\etc"
redirect = "127.0.0.1"
website_list = ["www.facebook.com", "facebook.com"]

while True:
    if dt(dt.now().year, dt.now().month, dt.now().day, 8) < dt.now() < dt(dt.now().year, dt.now().month, dt.now().day, 18):
        print ("Working hours..")
        with open(host_temp,'r+') as file:
            content=file.read()
            for website in website_list:
                if website in content:
                    pass
                else:
                    file.write(redirect + " " + website+ "\n")
    else:
        with open(host_temp, 'r+') as file:
            content= file.readlines()
            file.seek(0)
            for line in content:
                if not any(website in line for website in website_list):
                    file.write(line)
            file.truncate()
        print("Fun hours..")
    time.sleep(5)