def bubble_sort( the_seq ):
    '''Sinks the largest item to the bottom in each round'''
    '''The iterations stop when there is no more swap'''
    n = len( the_seq )
    for i in range( n - 1, 0, -1 ) :
        swap = False
        for j in range( i ) :
            if the_seq[j] > the_seq[j + 1] :
                # swap the two items 
                tmp = the_seq[j] 
                the_seq[j] = the_seq[j + 1]
                the_seq[j + 1] = tmp
                swap = True
        if swap == False:  # everything is in order
            break