index.py 文件源码

def _generate_regular_range(start, end, periods, offset):
    if isinstance(offset, Tick):
        stride = offset.nanos
        if periods is None:
            b = Timestamp(start).value
            # cannot just use e = Timestamp(end) + 1 because arange breaks when
            # stride is too large, see GH10887
            e = b + (Timestamp(end).value - b) // stride * stride + stride // 2
            # end.tz == start.tz by this point due to _generate implementation
            tz = start.tz
        elif start is not None:
            b = Timestamp(start).value
            e = b + np.int64(periods) * stride
            tz = start.tz
        elif end is not None:
            e = Timestamp(end).value + stride
            b = e - np.int64(periods) * stride
            tz = end.tz
        else:
            raise ValueError("at least 'start' or 'end' should be specified "
                             "if a 'period' is given.")

        data = np.arange(b, e, stride, dtype=np.int64)
        data = DatetimeIndex._simple_new(data, None, tz=tz)
    else:
        if isinstance(start, Timestamp):
            start = start.to_pydatetime()

        if isinstance(end, Timestamp):
            end = end.to_pydatetime()

        xdr = generate_range(start=start, end=end,
                             periods=periods, offset=offset)

        dates = list(xdr)
        # utc = len(dates) > 0 and dates[0].tzinfo is not None
        data = tools.to_datetime(dates)

    return data