while True:
    stock = Share('XLV')
a = stock.get_historical('2016-05-23', '2016-05-23')[0]['Close']
b = stock.get_prev_close()
r = requests.get(hist_url)
reader = csv.DictReader(r.iter_lines())
c = float(next(reader)['Close'])
d = float(requests.get(realtime_url).text)
print(datetime.datetime.now(eastern).time(), a, b, c, d)
time.sleep(120)
Неверные данные закрытия из yahoo_finance в python