def disk_io_counters():
    """Return disk I/O statistics for every disk installed on the
    system as a dict of raw tuples.
    """
    # man iostat states that sectors are equivalent with blocks and
    # have a size of 512 bytes since 2.4 kernels. This value is
    # needed to calculate the amount of disk I/O in bytes.
    SECTOR_SIZE = 512

    # determine partitions we want to look for
    partitions = []
    f = open("/proc/partitions", "r")
    try:
        lines = f.readlines()[2:]
    finally:
        f.close()
    for line in lines:
        _, _, _, name = line.split()
        if name[-1].isdigit():
            partitions.append(name)
    #
    retdict = {}
    f = open("/proc/diskstats", "r")
    try:
        lines = f.readlines()
    finally:
        f.close()
    for line in lines:
        _, _, name, reads, _, rbytes, rtime, writes, _, wbytes, wtime = \
            line.split()[:11]
        if name < partitions:
            rbytes = int(rbytes) * SECTOR_SIZE
            wbytes = int(wbytes) * SECTOR_SIZE
            reads = int(reads)
            writes = int(writes)
            # TODO: times are expressed in milliseconds while OSX/BSD has
            # these expressed in nanoseconds; figure this out.
            rtime = int(rtime)
            wtime = int(wtime)
            retdict[name] = (reads, writes, rbytes, wbytes, rtime, wtime)
    return retdict


# taken from /fs/proc/array.c
dataset/ETHPy150Open packages/psutil/psutil/_pslinux.py/disk_io_counters/operator `in` -> `<`