#伪代码
def  bubble_sort(numbers):
    """Sorts a list of numbers using bubble_sort """
    while True:
        #start off asuming it's sorted
        #comparing 2 at a time ,skipping around
        #loop through comparing node to the end
            #if the next is greater ,then we need to swap
            #oops,look like we have to scan again
        #this is reset at the top but if we never swapped,it's sorted
