Notificador de cambio de cotización | Brou | Gales

notifycotiz.py

import os
import sys
import time
import urllib
import pynotify
import cPickle
import signal

from scrapy.selector import HtmlXPathSelector

COTIZHOME = "%s/.notifycotiz" % os.getenv('HOME')
COTIZDB = "cotizaciones.pickle"

def get_cotizacion_moneda(html, main_xpath, compra_xpath, venta_xpath):
    hsel = HtmlXPathSelector(text=html)
    cotiz = hsel.select(main_xpath)

    return {
        'compra': float(cotiz.select(compra_xpath).extract()[0].replace(',', '.')),
        'venta': float(cotiz.select(venta_xpath).extract()[0].replace(',', '.'))
    }

def _cotizacion_dolar_brou(html):
    return get_cotizacion_moneda(html, "//td[@id='column-2']//div[@id='exchangeRatesLarge']/table/tr[2]",
        "td[@class='buy']/text()", "td[@class='sale']/text()")

def _cotizacion_dolar_gales(html):
    return get_cotizacion_moneda(html, "//table[@class='monedas']/tr[1]",
        "td[2]/text()", "td[3]/text()")

SOURCES = [
    ('brou', 'http://brou.com.uy/web/guest/institucional/cotizaciones', _cotizacion_dolar_brou),
    ('gales', 'http://gales.com.uy/home/', _cotizacion_dolar_gales),
]

def notify(title, msg):
    """Simple wrapper around pynotify OSD"""
    n = pynotify.Notification(title, msg)
    if not n.show():
        print "Fail to show notification"
        del n
        sys.exit(1)
    del n


def main():
    if not pynotify.init("Basics"):
        print "Can't initialize PyNotify"
        sys.exit(1)

    if not os.path.exists(COTIZHOME):
        os.mkdir(COTIZHOME)

    dbpath = os.path.join(COTIZHOME, COTIZDB)
    cotizs = {}
    if os.path.exists(dbpath):
        try:
            cotizs = cPickle.load(open(dbpath))
        except EOFError, UnpicklingError:
            pass

    def _format_cotiz(cotizs):
        if not cotizs:
            return ""
        last = "\n".join("[%s] %.2f - %.2f" % (src, v['compra'], v['venta']) for src, v in cotizs.items())
        return "Dolar\n%s" % last

    def _handler(signum, frame):
        print "Exiting applicatin gracefully..."
        print "Saving data ..."
        with open(dbpath, 'w') as db:
            cPickle.dump(cotizs, db)
        print "Saved!"

        print "Bye!"
        sys.exit(1)
    signal.signal(signal.SIGINT, _handler)

    while True:
        notify("Obteniendo cotizaciones ...", _format_cotiz(cotizs))
        for src, url, fun in SOURCES:
            html = urllib.urlopen(url).read()
            print >>sys.stderr, "Get data from [%s] : [%s]" % (src, url)
            try:
                dolar = fun(html)
            except Exception, e:
                print >>sys.stderr, "ERROR: getting data from [%s], exc: %s" % (src, e.msg)
            if src not in cotizs:
                cotizs[src] = dolar
            oldcotiz = cotizs[src]
            if oldcotiz['compra'] != dolar['compra'] or oldcotiz['venta'] != dolar['venta']:
                ncotiz = "Vieja: %.2f - %.2f\nNueva: %.2f - %.2f" % (oldcotiz['compra'], oldcotiz['venta'],
                    dolar['compra'], dolar['venta'])
                notify("[%s] Cotizacion cambio" % src.upper(), ncotiz)
            cotizs[src] = dolar
        with open(dbpath, 'w') as db:
            cPickle.dump(cotizs, db)
        time.sleep(300)

if __name__ == '__main__':
    main()