Checks Bitstamp API for latest price and produces a Pushover notification if price exceeds defined limits

gistfile1.py

# -*- coding: utf-8 -*-
"""
Created on Tue Oct  1 10:20:23 2013
  ----------------------------------------------------------------------------
  "THE BEER-WARE LICENSE" (Revision 42):
  voneiden <gmail:snaipperi> wrote this file. As long as you retain this notice you
  can do whatever you want with this stuff. If we meet some day, and you think
  this stuff is worth it, you can buy me a beer in return
  ----------------------------------------------------------------------------
 
"""
import decimal

# Change these to edit alert tresholds
# After an alert has been issued, a new number must be chosen
# for a new alert
low = decimal.Decimal("500.0")
high = decimal.Decimal("550.0")

import json
import os
import pickle
import sys
import urllib


def alert(title, msg, priority=0):
    import httplib
    conn = httplib.HTTPSConnection("api.pushover.net:443")
    conn.request("POST", "/1/messages.json",
             urllib.urlencode({
             "token": "CHANGE TO PUSHOVER TOKEN", #<--- change this
             "user": "CHANGE TO PUSHOVER USER",   #<--- change this
             u"message": msg,
             "title":title,
             "priority":priority,
             }), { "Content-type": "application/x-www-form-urlencoded" })
    r = conn.getresponse()
    r.read()


# Bitstamp's API has blocked python urllib user-agent.
# Changing the user-agent seemed like too much hassle for me
# So I use wget instead. Change the  destination folder

destination_folder = "/home/voneiden/src"
destination_file = "%s/index.html"%(destination_folder)
pickle_file = "%s/btcstamp.db"%(destination_folder)

os.system("wget -qP %s https://www.bitstamp.net/api/ticker/"%(destination_folder))
try:
    f = open(destination_file, "r")
except IOError: 
    # Sometimes wget doesn't get the file. Bitstamp being a jerk.
    # You might wanna retry, but I don't bother. Just quit.
    print "IO ERROR"
    sys.exit(1)
    
source = f.read()
f.close()
os.remove(destination_file)

data = json.loads(source)

price = decimal.Decimal(data["last"])


try:
    f = open(pickle_file,'r')
    db = pickle.load(f)
    f.close()
except:
    print "Database not found, creating"
    db = {'low':decimal.Decimal("0"),
          "high":decimal.Decimal("0")}

def dump(db, pickle_file):
	f = open(pickle_file,"w")
	pickle.dump(db,f)
	f.close()
          
    
if price >= high and high != db["high"]:
    db["high"] = high
    alert("BITSTAMP", "HIGH! Over $%s"%high)
    dump(db, pickle_file)
    
if price <= low and low != db["low"]:
    db["low"] = low
    alert("BITSTAMP", "LOW! Below $%s"%low,1) # Priority alert
    dump(db, pickle_file)