def get_exchange_rate(input_currency, output_currency):
"""Gets the exchange rate as output_currency per input_currency.
Caches the result for five minutes.
"""
input_currency = input_currency.upper()
output_currency = output_currency.upper()
key = '%s_per_%s' % (output_currency, input_currency)
rate = cache.get(key)
if rate is None:
rate = _query_exchange_rate(input_currency, output_currency)
cache.set(key, rate, timeout=300)
# TODO: cache the inverse while we have it?
return rate
def get_exchange_rate(input_currency, output_currency):
"""Gets the exchange rate as output_currency per input_currency.
Caches the result for five minutes.
"""
input_currency = input_currency.upper()
output_currency = output_currency.upper()
key = '%s_per_%s' % (output_currency, input_currency)
rate = cache.get(key)
if rate is None:
rate = _query_exchange_rate(input_currency, output_currency)
cache.set(key, rate, timeout=300)
# TODO: cache the inverse while we have it?
return rate
def get_usd_per_btc():
"""Get current exchange rate as a float.
Caches the exchange rate for five minutes.
"""
usd_per_btc = cache.get('usd_per_btc')
if usd_per_btc is None:
url = 'https://api.bitcoinaverage.com/ticker/USD/'
r = requests.get(url)
data = r.json()
usd_per_btc = float(data['24h_avg'])
cache.set('usd_per_btc', usd_per_btc, timeout=300)
return usd_per_btc
def get_usd_per_ltc():
"""Get current exchange rate as a float.
Caches the exchange rate for five minutes.
"""
usd_per_ltc = cache.get('usd_per_ltc')
if usd_per_ltc is None:
url = 'https://btc-e.com/api/2/ltc_usd/ticker'
r = requests.get(url)
data = r.json()
usd_per_ltc = float(data['ticker']['avg'])
urlfh.close()
cache.set('usd_per_ltc', usd_per_ltc, timeout=300)
return usd_per_ltc
def get_image_io(dpr, price, currency, color):
"""Get the StringIO object containing the image.
Also cached, with a name containing the BTC price and color."""
img_name = 'img_{0:f}_{1}_{2}[0]_{2}[1]_{2}[2]_{3}x'.format(price, currency, color, dpr)
img_io = cache.get(img_name)
if img_io is None:
img = generate_image(dpr, price, currency, color)
img_io = StringIO()
img_io.write(img)
img_io.seek(0)
cache.set(img_name, img_io, timeout=300)
img_io.seek(0)
return img_io
def get_image_io(price, currency, color):
"""Get the StringIO object containing the image.
Also cached, with a name containing the BTC price and color."""
img_name = 'img_{0:f}_{1}_{2}[0]_{2}[1]_{2}[2]'.format(price, currency, color)
img_io = cache.get(img_name)
if img_io is None:
img = generate_image(price, currency, color)
img_io = StringIO()
img_io.write(img)
img_io.seek(0)
cache.set(img_name, img_io, timeout=300)
img_io.seek(0)
return img_io
def get_exchange_rate(input_currency, output_currency):
"""Gets the exchange rate as output_currency per input_currency.
Caches the result for five minutes.
"""
input_currency = input_currency.lower()
output_currency = output_currency.lower()
key = '%s_per_%s' % (output_currency, input_currency)
rate = cache.get(key)
if rate is None:
if output_currency == 'btc':
rate = get_btc_rate(input_currency)
elif output_currency == 'ltc' and input_currency == 'usd':
rate = get_ltc_per_usd()
else:
raise ValueError('unsupported currency pair')
cache.set(key, rate, timeout=300)
# TODO: cache the inverse while we have it?
return rate
