lib/exchange_rate.py

   1 from PyQt4.QtCore import SIGNAL
   2 import decimal
   3 import httplib
   4 import json
   5 import threading
   6
   7 class Exchanger(threading.Thread):
   8
   9     def __init__(self, parent):
  10         threading.Thread.__init__(self)
  11         self.daemon = True
  12         self.parent = parent
  13         self.quote_currencies = None
  14         self.lock = threading.Lock()
  15         # Do price discovery
  16         self.start()
  17
  18     def exchange(self, btc_amount, quote_currency):
  19         with self.lock:
  20             if self.quote_currencies is None:
  21                 return None
  22             quote_currencies = self.quote_currencies.copy()
  23         if quote_currency not in quote_currencies:
  24             return None
  25         return btc_amount * quote_currencies[quote_currency]
  26
  27     def run(self):
  28         self.discovery()
  29
  30     def discovery(self):
  31         try:
  32             connection = httplib.HTTPSConnection('blockchain.info')
  33             connection.request("GET", "/ticker")
  34         except:
  35             return
  36         response = connection.getresponse()
  37         if response.reason == httplib.responses[httplib.NOT_FOUND]:
  38             return
  39         response = json.loads(response.read())
  40         quote_currencies = {}
  41         try:
  42             for r in response:
  43                 quote_currencies[r] = self._lookup_rate(response, r)
  44             with self.lock:
  45                 self.quote_currencies = quote_currencies
  46             self.parent.emit(SIGNAL("refresh_balance()"))
  47         except KeyError:
  48             pass
  49
  50     def get_currencies(self):
  51         return [] if self.quote_currencies == None else sorted(self.quote_currencies.keys())
  52
  53     def _lookup_rate(self, response, quote_id):
  54         return decimal.Decimal(str(response[str(quote_id)]["15m"]))
  55
  56 if __name__ == "__main__":
  57     exch = Exchanger(("BRL", "CNY", "EUR", "GBP", "RUB", "USD"))
  58     print exch.exchange(1, "EUR")
  59