bubble_sort.py

# Bubble Sort Algorithm - sort a sequence in place, for additional convenience
# returns the sequence.
# Time complexity: n^2

# For descending sort change the comparison symbol on line 13:
# if seq[i] > seq[i-1]

# Script is intended to be run with Python3, but is Python2 compatible.
# If running the script with Python2, range() function will return a list.
# Consider changing it to xrange(), if running with Python2.


def bubble_sort(seq):
    length = len(seq)
    for j in range(length):
        for i in range(length-1, j, -1):
            if seq[i] < seq[i-1]:
                seq[i], seq[i-1] = seq[i-1], seq[i]
    return seq


if __name__ == '__main__':
    seq = [5, 7, 1, 9, 3, 7, 8]
    print(bubble_sort(seq))