Insertion Sort In Python Explained (With Example And Code) 

Absolutely beautiful ,a simple and concise explanation ,Wish I had teachers like you.

OMG! I've only watched a few mins of your video and I can't believe what a great job you did on the explanation and the beauty, pace, and clarity of the presentation! Top-notch! You really need to continue being a Tech Trainer either FT or on the side, as you are VERY GOOD at it!

ive been using your channel to study for coding interviews, most simple explanations out there, ty!

I found this coding example is the easiest yet most efficient one out there! Thank you Felix!

I’m reading a book for school and the problem had 2x as much code wayyyyy harder than it had to be… thanks man!!

You made this look so easy dude ... thanks a lot

thanks a lot for this simple code man .......a lot of sites on the internet had to many complicated codes but this one was small and simple :)

❤❤❤❤ the simplest video have seen so far that made this so simple. I have watched dozens of videos at a point I said I will never use insertions sort 😅

This is literally a lifesaver. Thank u.

I have been running away from this Sorting and Searching since 2011(Pre University Years), I am in the 6th year of my career and TIL "SORTING", which is simple and non-scary. Thank you!

Really nice and clean code! Good work!

I LOVE YOU SO MUCH MAN YOU'RE A LIFESAVER WISH ME LUCK I HAVE AN EXAM ON TUESDAY

please make more videos like this for more concepts like Job scheduling with Greedy method , Knapsack problems, Travelling salesman Problems etc , it will be very useful for many tech enthusiasts 🙏🏻

only till I watched this video did I know that there are two loops, one to the right and one to the left. Thank you for saving my life

A perfect explanation and elegant coding solution

Very clear explanation, thank you so much!

very Informative and simple.. Loved your explanation..

Brilliant explanation. Thank you!

Thank you man . Best explanation , easy to understand

Perfect explanation, Thank you sir!

Thankyou it's really great keep it up:)

Very nice, just what I needed, thanks!

Eloquent, beautiful. Thanks

very good explanation and very understandable code!

Thanks brother, This helped me a lot

Thank you so much, im grateful

thanks a lot brother!

thank you for explaining this in a simple way 🙏🏼

Thank you! Thank you! Thank you!

Good explanation 👏👍

best video on youtube.

I found your code simple but but i dont think it is the correct example of insertion sort. bcz in insertion sort, we pick one element and put it to its correct location, but you kept swapping the element with the previous element until the previous element is not smaller than our main element. So it is technically an example of bubble sort that is executed in the reverse direction. You won't get what im trying to say just by reading my sentence. Therefore look at this example of insertion sort : l1 = [5,1,3,4,2] n = len(l1) for i in range(n): k = l1[i] j = i-1 while k=0 : l1[j+1] = l1[j] j -= 1 else: l1[j+1] = k print('Sorted list: ', l1)

Is there any reason you would want to use this instead of the built in sort function in Python?

muy buena explicacion, gracias por el video

brilliant!!!

Be continue bro.

a good explanation!

New to coding. Curious why you used i in your for loop and then set j to i instead of just using j to iterate through?

Thank you man

Thank you!!

superb master

I was told that in insertion sort we don't make a swap and we only move the elements greater than the current to the right next position until we reach the current correct position. Does that explanation make sense? or the swap action is the same that the shift action?

Love from prayagraj

aside from readability, which in this case I don't think is a win, you don't need to even define j because if you think about it j is just i, so the code could be written as: def iterative_insertion_sort(arr: list): for i in range(1, len(arr)): while arr[i-1] > arr[i] and i > 0: arr[i-1], arr[i] = arr[i], arr[i-1] i -= 1 This code block passes all my unit tests of which I have 14. I'll list them below. One thing Felix does which I haven't seen anyone else do is instead of comparing right to left he actually compares left to right. I guess it doesn't matter. My mind makes easier send of things as right to left, especially since you're counting down *to the left* in terms of comparisons. Anyway...no need for j. from iterative_insertion_sort import iterative_insertion_sort import pytest def test_alternating_zeroes_and_ones(): arr = [0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1] assert iterative_insertion_sort(arr) == sorted(arr) def test_increasing_decreasing(): arr = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1] assert iterative_insertion_sort(arr) == sorted(arr) def test_decreasing_increasing(): arr = [19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1] + list(range(1, 20)) assert iterative_insertion_sort(arr) == sorted(arr) def test_all_but_one_element_the_same(): arr = [0] * 19 + [1] assert iterative_insertion_sort(arr) == sorted(arr) def test_all_but_one_element_the_same_big_delta(): arr = [1] * 19 + [100] assert iterative_insertion_sort(arr) == sorted(arr) def test_large_range(): arr = [-100] + list(range(1, 20)) assert iterative_insertion_sort(arr) == sorted(arr) def test_very_close_numbers(): arr = [i/10 for i in range(20)] assert iterative_insertion_sort(arr) == sorted(arr) def test_all_negative_numbers(): arr = list(range(0, -5, -1)) assert iterative_insertion_sort(arr) == sorted(arr) def test_mix_of_positive_and_negative(): arr = [-10, 10] * 10 assert iterative_insertion_sort(arr) == sorted(arr) def test_alternating_high_and_low(): arr = [20 - i if i % 2 == 0 else i for i in range(20)] assert iterative_insertion_sort(arr) == sorted(arr) def test_peak_in_the_middle(): arr = [2] * 10 + [3] + [2] * 9 assert iterative_insertion_sort(arr) == sorted(arr) def test_small_range_random_integers(): arr = [5, 3, 0, 4, 0, 4, 4, 0, 4, 0, 0, 0, 0, 4, 1, 0, 1, 4, 3, 5] assert iterative_insertion_sort(arr) == sorted(arr) def test_floating_point_numbers(): arr = [float(i) for i in range(20)] assert iterative_insertion_sort(arr) == sorted(arr) def test_large_value_at_the_beginning(): arr = [1000] + list(range(1, 20)) assert iterative_insertion_sort(arr) == sorted(arr)

Can you explain the condition used in program

thank you

Hey , I had a doubt cuz when I wrote this code it was showing list index out of range also why did we do j=-1 , if we are going from left to right so we are increasing the index we aren't going from right to left?

wow it working🥳

How does this have better presentation than my online university?

why would you call a for loop, which is slower iirc, instead of maybe append value to list then just call the sort on the array? I’m still learning efficiency

Hi. can this even more simpler version works? --> for i in range(0,len(lst)): while (lst[i-1]>lst[i] and i>0): lst[i-1],lst[i]=lst[i],lst[i-1] i-=1 print(lst)

I trust you and your console.

i have a question why u'v used while instead we can use for like that : def tri_insertion(L): for i in range(1,len(l)): for j in range(len(l[:i])): if l[i]

i caN Trust you now sir

tq bro .

There is actually an item at index -1 and it is the last element from the list

Thanks

Thank u

can someone explain whats j=i used for

how to print number 1,2,3,4,5 in ascending then descending order in a same line? the output should be 1,2,3,4,5,4,3,2,1. can you help?

Why does j need to be used, cant i just be used instead?

Why do you need to define a new variable j? You can just ignore j and use i. Am i wrong?

why did we check if j is greater than zero ? we start the loop from zero

may you explain more about j=j-1 ? should it decreasing from last element ?

Sir continue the series in leetcode

hey can u give the code so i can copy and paste cause mine's not working

This seems like an inefficient bubble sort algo

😎🤝

Noice.

Not showing the output

I didn't knew that Felix had started a programming channel apart from his PEWDIEPIE channel. But my doubt, is why is he having so less SUBSCRIBERS......... 😂

Does this work with numbers larger than 9?

❤❤❤❤❤

Super good!

Timestamps/suggested chapters: 0:00 Intro 0:08 Overview 0:31 Example 3:21 Code 7:44 Outro

Can anyone explain why we put the j-=1?

Better and shorter than the one of my teacher 👌😅

insertion sort perform shift operations rather than swap.

All is fine, but I'm not sure why did you create a 'j' that is 'i'? I removed the 'j' variable and the result is just the same. Is it due to some common or PEP practices or a different Python version?

this code is not worked

if anyone else is here cuz of faris foo like this comment

Thanks