なぜカウンターコードはカウントごとに余分な行を追加するのですか？

Question

このコードの何が問題になっているのですか？カウントアップまたはカウントダウンするたびに余分な行が追加されます。

def counter(start, stop):
    x = start
    if start > stop:
        return_string = "Counting down: "
        while x >= stop:
            return_string += str(x)
            x = x-1 
            if start != stop:
                return_string += ","
            print(return_string)
    else:
        return_string = "Counting up: "
        while x <= stop:
            return_string += str(x)
            x = x + 1 
            if start != stop:
                return_string += ","
            print(return_string)
    return return_string

print(counter(1, 10)) # Should be "Counting up: 1,2,3,4,5,6,7,8,9,10"
print(counter(2, 1)) # Should be "Counting down: 2,1"
print(counter(5, 5)) # Should be "Counting up: 5"

Answer 1

def counter(start, stop):
x = start
if start > stop:
    return_string = "Counting down: "
    while x >= stop:
        return_string += str(x)
        x = x - 1
        if x >= stop:
            return_string += ","
else:
    return_string = "Counting up: "
    while x <= stop:
        return_string += str(x)
        x = x + 1
        if x <= stop:
            return_string += ","
return return_string

Answer 2

ここにある：

def counter(start, stop):
    x = start
    if start>stop:

        return_string = "\"Counting down: "
        while x >= stop:
            return_string += str(x)
            x=x-1
            if x>=stop:
                return_string += ","
        return_string += '"'
    else:
        return_string = "\"Counting up: "
        while x <= stop:
            return_string += str(x)
            x=x+1
            if x<=stop:
                return_string += ","
        return_string += '"'
    return return_string