# Selection Sort

This might not be the most efficient implementation of the selection sort algorithm. However, it is the one that closely matches how the algorithm is explained:

- Pick up the first card (if this was a deck of cards).
- Compare the card in your hand to each other card in turn
- If a smaller card is found, swap the cards (so the smaller card is now in your hand).
- When you get to the last card, put the card in your hand into a separate pile.
- Repeat steps 1-4 until there are no more cards in the original deck

Want to learn more? I recommend these Python books: Python for Data Analysis, Python Data Science Handbook, and Introduction to Machine Learning with Python.

## Create A Sequence

alist = [8,5,3,6,2,1,9,4,7] alist

[8, 5, 3, 6, 2, 1, 9, 4, 7]

## Create A Selection Sort Algorithm

# Define a function that takes an unsorted list, def selection_sort(alist): # Create a new list containing the values from the inputed list unsorted_sequence = alist[:] # Create a list where we will place the sorted values sorted_sequence = [] # While there are still values in the unsorted sequence: while len(unsorted_sequence) > 0: # For each value in the unsorted sequence, for i, _ in enumerate(unsorted_sequence): # Assume it is the smallest value smallest_value_index = i # Compare it which each other value in the unsorted list for i, _ in enumerate(unsorted_sequence): # If a smaller value is found if unsorted_sequence[smallest_value_index] > unsorted_sequence[i]: # Swap the two values so the new value is the one we think is the smallest smallest_value_index, i = i, smallest_value_index # When we get to the end of the sequence, remove the smallest valued card smallest_value = unsorted_sequence.pop(smallest_value_index) # And add it to our sequence of sorted values sorted_sequence.append(smallest_value) # Print the sorted sequence print('Sorted sequence so far:', sorted_sequence)

# Run the selection sort selection_sort(alist)

Sorted sequence so far: [1] Sorted sequence so far: [1, 2] Sorted sequence so far: [1, 2, 3] Sorted sequence so far: [1, 2, 3, 4] Sorted sequence so far: [1, 2, 3, 4, 5] Sorted sequence so far: [1, 2, 3, 4, 5, 6] Sorted sequence so far: [1, 2, 3, 4, 5, 6, 7] Sorted sequence so far: [1, 2, 3, 4, 5, 6, 7, 8] Sorted sequence so far: [1, 2, 3, 4, 5, 6, 7, 8, 9]