def diskstats():
    file_path = '/proc/diskstats'

    # http://lxr.osuosl.org/source/Documentation/iostats.txt
    columns_disk = ['major_dev_num', 'minor_dev_num', 'device', 'reads', 'reads_merged', 'sectors_read', 'ms_reading', 'writes', 'writes_merged', 'sectors_written', 'ms_writing', 'current_ios', 'ms_doing_io', 'weighted_ms_doing_io']
    columns_partition = ['major_dev_num', 'minor_dev_num', 'device', 'reads', 'sectors_read', 'writes', 'sectors_written']

    result = {}
    for line in (l for l in open(file_path, 'r').xreadlines() if l != ''):
        parts = line.split()
        if len(parts) == len(columns_disk):
            columns = columns_disk
        elif len(parts) == len(columns_partition):
            columns = columns_partition
        else:
            continue
        data = dict(zip(columns_disk, parts))
        result[data['device']] = dict((k, int(v)) for k, v in data.iteritems() if k != 'device')
    return result

if __name__ == '__main__':
    for device, stats in diskstats().iteritems():
        print device
        for name, stat in stats.iteritems():
            print '    %s: %s' % (name.replace('_', ' '), stat)
    # See http://www.xaprb.com/blog/2010/01/09/how-linux-iostat-computes-its-results/ for how to make the output more iostats-y