def bubble_sort(collection):
    """Pure implementation of bubble sort algorithm in Python

    :param collection: some mutable ordered collection with heterogeneous
    comparable items inside
    :return: the same collection ordered by ascending

    Examples:
    >>> bubble_sort([0, 5, 3, 2, 2])
    [0, 2, 2, 3, 5]

    >>> bubble_sort([])
    []

    >>> bubble_sort([-2, -5, -45])
    [-45, -5, -2]

    >>> bubble_sort([-23, 0, 6, -4, 34])
    [-23, -4, 0, 6, 34]

    >>> bubble_sort([-23, 0, 6, -4, 34]) == sorted([-23, 0, 6, -4, 34])
    True
    """
    length = len(collection)
    for i in range(length-1):
        swapped = False
        for j in range(length-1-i):
            if collection[j] > collection[j+1]:
                swapped = True
                collection[j], collection[j+1] = collection[j+1], collection[j]
        if not swapped:
            break  # Stop iteration if the collection is sorted.
    return collection


if __name__ == '__main__':
    user_input = input('Enter numbers separated by a comma:').strip()
    unsorted = [int(item) for item in user_input.split(',')]
    print(*bubble_sort(unsorted), sep=',')