Combine Two Recursive Functions To Create One Recursive Selection Sort Function

[Jeremy7]

def selection_sort(lst):
    result = []
    while lst:
        element = lst[0]
        for i in range(1, len(lst)):
            if lst[i] < element:
                element = lst[i]
        lst.remove(element)
        result.append(element)
    return result

Hi Serafim, in your "for loop" in this code, what is the purpose of the "1" in "(1, len(lst))," because as I was studying the code to see how everything worked together to sort the list, I couldn't figure out what the purpose of the "1" was, so I deleted it to see if the code would still work, and it still works?

[Serafim]

Hi Serafim, in your "for loop" in this code, what is the purpose of the "1" in "(1, len(lst))," because as I was studying the code to see how everything worked together to sort the list, I couldn't figure out what the purpose of the "1" was, so I deleted it to see if the code would still work, and it still works?

range(len(lst)) means [0, 1, 2, ..., len(lst)-1] and range(1, len(lst)) starts at 1, giving [1, 2, ..., len(lst)-1] and as I use lst[0] as start value (element = lst[0]) I would, in the first step compare lst[0] < lst[0] if the loop was over range(len(lst)), which I know is false so I just skip that first step. It works with both constructs but my way skips one unnecessary test. Old programming habit, minimize work if obvious.

[Jeremy7]

range(len(lst)) means [0, 1, 2, ..., len(lst)-1] and range(1, len(lst)) starts at 1, giving [1, 2, ..., len(lst)-1] and as I use lst[0] as start value (element = lst[0]) I would, in the first step compare lst[0] < lst[0] if the loop was over range(len(lst)), which I know is false so I just skip that first step. It works with both constructs but my way skips one unnecessary test. Old programming habit, minimize work if obvious.

Oooh! I see! It makes sense. Not only removing one unnecessary step, but making the code efficient, and I'm all about efficiency. I'm learning, and this learning curve is HUGE right now; I'll be glad when it shrinks to the size of a needle point. Just started learning Python in November 2020, and even though I attained an associate’s degree in computer programming in 2016, I had no clue then how code worked, it was just over my head, so it's like all new to me. And I was able to attain my degree because so many people helped me get through the courses. Sadly, I didn't learn anything in computer programming, except how variables worked; I just got through the programming courses. That's sad. So as you can see by me asking you about the "1" in (1, len(lst)), I had no clue how the code was actually working to sort the list, but with that simple explanation of why "1" is in there, now I see how it works; I see the WHOLE code; I see how all the dots connect. YAAAHOOO!!! Thanks again!