why counter code add extra line every count?

Question

what is wrong with this code it adds extra line each time it count up or down how can i prevent that and why it's happening ?

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

Use this :

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