watch_site - GitPress.io

Example Python program watch_site.py

Modules

import datetime
import os
import os.path
import time
import urllib2
import Tkinter

Classes

class AlertWindow(Tkinter.Toplevel):
class MainWindow(Tkinter.Tk):

Methods

def now():
def init(self, message):
def init(self):
def quit_handler(self, event=None):
def start_timer(self):
def get_url(self):
def first_check(self):
def check_for_changes(self):
def main():

Code

Python tkinter example

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# vi:ts=4 sw=4 et

import datetime
import os
import os.path
import time
import urllib2

import Tkinter


SITE_URL = "http://equipe.nce.ufrj.br/eber/FES20102/default2.htm"
TIME_BETWEEN_CHECKS = 10*60*1000  # 10min * 60s * 1000ms





def now():
    return datetime.datetime.now().strftime("%H:%M")


class AlertWindow(Tkinter.Toplevel):
    def __init__(self, message):
        Tkinter.Toplevel.__init__(self)

        self.title(message)

        self.message = Tkinter.StringVar()
        self.message.set(message)

        self.message_label = Tkinter.Label(self, textvariable=self.message, anchor='w', justify='left', padx=32, pady=32)
        self.message_label.pack(fill='both', expand=1)


class MainWindow(Tkinter.Tk):
    def __init__(self):
        Tkinter.Tk.__init__(self)

        self.after_id = None
        self.compare_against = ""

        self.title("Watching a site...")

        self.header_label = Tkinter.Label(self, text=u"Watching this URL for changes every {1} seconds:\n{0}".format(SITE_URL, TIME_BETWEEN_CHECKS//1000), anchor='w', justify='left')
        self.header_label.pack(fill='both', expand=1)

        self.message = Tkinter.StringVar()
        self.message_label = Tkinter.Label(self, textvariable=self.message, anchor='w', justify='left')
        self.message_label.pack(fill='both', expand=1)

        # Global quit handlers
        self.bind_all("<Control-q>", self.quit_handler)
        self.protocol("WM_DELETE_WINDOW", self.quit_handler)

    def quit_handler(self, event=None):
        self.destroy()

    def start_timer(self):
        self.after_id = self.after(TIME_BETWEEN_CHECKS, self.check_for_changes)

    def get_url(self):
        return urllib2.urlopen(SITE_URL).read()

    def first_check(self):
        try:
            self.message.set(u"[{0}] Getting the inital data...".format(now()))
            self.compare_against = self.get_url()
            self.start_timer()
            self.message.set(u"[{0}] Waiting for the next check...".format(now()))
        except urllib2.URLError as e:
            self.message.set(u"[{0}] Error while getting the inital data:\n{1}\nThis program won't work, please restart it.".format(now(), e.reason))

    def check_for_changes(self):
        try:
            self.message.set(u"[{0}] Checking URL...".format(now()))
            new_data = self.get_url()

            if new_data == self.compare_against:
                self.start_timer()
                self.message.set(u"[{0}] No changes yet. Waiting for the next check...".format(now()))
            else:
                self.message.set(u"[{0}] The contents have been changed! \\o/".format(now()))
                self.message_label.config(fg="red")
                self.alert_window = AlertWindow(u"[{0}] The contents have been changed! \\o/".format(now()))

        except urllib2.URLError as e:
            self.start_timer()
            self.message.set(u"[{0}] Error while getting the URL:\n{1}\nTrying again later...".format(now(), e.reason))


def main():
    win = MainWindow()
    win.first_check()
    win.mainloop()


if __name__ == "__main__":
    main()

Useful Links

Articles: https://python-commandments.org/
Python shell: https://bsdnerds.org/learn-python/
Tutorial: https://pythonprogramminglanguage.com/