code: def tail(filename, n):
    
    size = os.path.getsize(filename)
    with open(filename, "rb") as f:
     fm = mmap.mmap(f.fileno(), 0, mmap.MAP_SHARED, mmap.PROT_READ)
     try:
        for i in xrange(size - 1, -1, -1):
            if fm[i] == '\n':
               n -= 1
               if n == -1:
                  break
        return fm[i + 1 if i else 0:].splitlines()
     finally:
          fm.close()
docs: Returns last n lines from the filename. No exception handling