Poloniex has a public API to retrieve exchange rate as shown here.
This script prints exchange rate for all currencies.
import json, urllib
url ="https://poloniex.com/public?command=returnTicker"
raw =json.load(urllib.urlopen(url))
data = {}
for key in raw:
if not key.startswith('BTC_'):
continue
data[key.strip('BTC_')] = float(raw[key]['last'])
print data
Output goes like this:
{u'STEEM': 0.00081724, u'PAS': 0.00042701, u'FLO': 4.149e-05, u'OMNI': 0.02931338, u'DG': 1.034e-05, u'REP': 0.01139999, u'URS': 8.44e-06, u'HU': 9.808e-05, u'GAME': 0.00167999, u'NAV': 0.0001808, u'EXP': 0.00146501, u'NAU': 0.000174, u'ETH': 0.12010002, u'GNO': 0.08499997, u'D': 0.03306394, u'NOTE': 6.228e-05, u'PP': 0.00120087, u'NM': 0.001316, u'SJCX': 0.0004077, u'LSK': 0.00125311, u'FLD': 1.238e-05, u'NX': 0.00014212, u'AMP': 0.0002445, u'X': 0.03436028, u'DCR': 0.016973, u'RI': 7.803e-05, u'LK': 0.00018638, u'E': 0.00716619, u'GR': 3.179e-05, u'XPM': 0.000285, u'F': 0.01223333, u'ZE': 0.13816714, u'ELA': 0.00013196, u'M': 0.00065487, u'L': 0.01662, u'N': 1.21e-06, u'DASH': 0.06811073, u'NEOS': 0.00236009, u'S': 0.00011355, u'STR': 1.464e-05, u'V': 0.000425, u'Y': 0.00028538, u'GN': 0.00023817, u'XV': 0.00021081, u'XRP': 0.00010752, u'XMR': 0.01854664, u'PINK': 9.01e-06, u'LAM': 0.00225963, u'VIA': 0.00063616, u'XEM': 7.125e-05, u'DOGE': 1.11e-06, u'VR': 0.00021135, u'PO': 5.123e-05, u'SYS': 8.85e-05, u'MAID': 0.00020392, u'XCP': 0.00664439, u'ARDR': 9.882e-05, u'RADS': 0.00271082, u'SBD': 0.00067313, u'EMC2': 3.223e-05, u'STRA': 0.0031399}
Enjoy!