在python中滚动中位数

numpy

numpy.nan

median = sum(sorted(a[-30:])[14:16]) / 2.0

a

median = numpy.median(a[-30:])

stock_data

last_thirty = stock_data[-30:]
median = sorted(last_thirty)[15]

stock_data

def rolling_median(data, window):
    if len(data) < window:
       subject = data[:]
    else:
       subject = data[-30:]
    return sorted(subject)[len(subject)/2]