

def asof_locs(self, where, mask):
    '\n        where : array of timestamps\n        mask : array of booleans where data is not NA\n\n        '
    locs = self.values[mask].searchsorted(where.values, side='right')
    locs = np.where((locs > 0), (locs - 1), 0)
    result = np.arange(len(self))[mask].take(locs)
    first = mask.argmax()
    result[((locs == 0) & (where < self.values[first]))] = (- 1)
    return result

dataset/ETHPy150Open pydata/pandas/pandas/indexes/base.py Index.asof_locs/original