def read_idx(response):
    """
    Read grib index file as list and insert row number into beginning
    """
    i = 0
    data = []
    lines = response.split(":\n")
    for line in lines:
        line_ = line.split(":")
        if len(line_) > 1:
            line_.insert(0, i)
            data.append(line_)
        i += 1
    return data