selection_sort.py

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

# 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 using Python3.
from __future__ import print_function


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

        if min_index != j:
            seq[j], seq[min_index] = seq[min_index], seq[j]
    return seq


if __name__ == '__main__':
    seq = [4, 10, 1, 6, 3, 8, 20, 7]
    print(selection_sort(seq))