Python OOP Tutorial 2: Class Variables

[@mtvcity2]

Your videos are more informative than my university lectures

[@coreyms]

Thanks a lot! That's a nice compliment. I'm glad to hear you find them useful.

[@silverzero9524]

and short and arent booooooring

[@MrZhunio]

This is so true. We obtain more information on those really short videos than we do in those long lectures on universities.

[@adityaverma6120]

True Story of every university

[@nicklesmatsch7588]

Well, kind of. In your videos we learn basically all the useful stuff we want to know, but in university we get all the side-information (sorry, no native speaker) we may find useful someday, even though we don't know yet, when it could happen.

[@팍준하]

Summary: In this video, Corey taught as how to differentiate between a Class variable and instance variable, how they are related to each, other, and when each of them is more useful over the other. Class variables are variables that we set inside a class, and are shared among all instances. Corey gave a good example where the number of total employs should be the same to every employ, no matter which employee we are referring to. Therefore, emp_1.num_of_employ = emp_2.num_of_employ = Employee.num_of_employ Instance variables are variables that are different from each instance. For example, the names and the pay for each employee. They have to be different. Corey also shows that class variables and instance variables are closely related, and that class variables are kind of 'inherited' to the 'self' variables. To illustrate this, Corey shows an example of 'annual raise of pay'. He initially creates the class variable to show a case where annual raise is equal among all the employees. This variable of 1.04 was accessible through each instance, and also through the class itself(obiviously). That is, print(Employee.annual_raise) print(emp_1.annual_raise) print(emp_2.anual_rais) all printed out 1.04. However, using the .__dict___ thing, Corey shows that the intances, emp_1 and emp_2 does not contain the annual_raise value. Corey explains that if a variable is not found within an instance and programmers try to access the variable, python automatically looks in in the variable of the instance's class, and then the more classes that the instance's class inherits from. Furthermore, if we access the class variable through an instance and then change it, python creates the variable within the instance. We can check it by using the .__dict__ thing. Corey shows that annual_raise key was created when he manually changed the annual_raise value as 1.05 in the following way. emp_1.annual_raise = 1.05 however, we know that the class variable remained the same at 1.04, when printing the class variable. print(Employee.annual_raise) ==> 1.04

[@marflage]

Thank you so much. I wanted to revise everything he said but did not want to watch the entire video again. Your comment helped me with just.

[@amansinghal2431]

in the second para you said that class variables are shared among all instances but I dont think thats the case. Corey said pyhton first searches the variables in the instance but if it doesnt find it, it goes to the class of the instance and returns it from their. if you dont explicitly mention emp1.raise_amount = 1.05, emp1 instance doesnt have the raise_amount vriables. Please confirm

[@infinitedeathloop5517]

@@amansinghal2431 I think he means, when the raise_amount variable isn't found in the instances, python searches for the instance in the class and applies it to both the instances, thus making them share the same variable. I hope I was clear

[@nishantthakur5357]

Thankx a lot mate

[@aniruddhkhare2080]

@@amansinghal2431 The fact that class variables are shared among instances is correct. When class variables are used in methods using class names (as in Employee.raise_amount), then python directly accesses the class namespace, which is common for every instance. But when self is used (as in self.raise_amount), then python first searches the object's namespace, and if not found, then the class namespace. That's why Corey states that using self allows to assign different class variable values to different objects, as reassigning them (such as self.raise_amount = 1.05), makes the value a part of the object's namespace which is queried first.

[@trevorduncan7913]

it really makes a difference who teaches you.....it was wtf wtf wtf....then watch these videos...oh ya that's logical. you are an awesome teacher....please keep the videos coming.

[@charlesbovalis6591]

Indeed - a "GOOD" teacher is PRICELESS !!!!!!

[@ismailmatrix1]

I noticed he uses a lot of printing to explain things. That's why it seems logical. When in doubt, just print it out!

[@selehadinhabesi3855]

well said, a teacher can kill or instill in you a love for a subject

[@HaroonAshrafAwan]

I enrolled into a top seller's python course on Udemy, read from some of the famous websites but I didn't find someone who teaches like you.You are, hands down, the best teacher anyone can have.

[@husainpersonal-o6y]

which course did you bought from udemu=y,can i know

[@michaelakingbade1036]

i made the same mistake

[@SS-lk7fs]

me too

[@ayeshavlogsfun]

Which Course did you buy .?

[@jaysphere7519]

@@ayeshavlogsfun I bought all. All of them below par compared to this.

[@nikolahuang1919]

This series is the best Python series I've ever watched. Your explanation is so clear and you just teach the right amount of useful knowledge we need.

[@coreyms]

Thanks!

[@petermaller4207]

可不是咋的！

[@takuz7879]

6 years later, and your videos are still helping us students. I'm in highschool and I'm literally studying for my exam through these. When I pass it'll all be because of you. THANK YOU COREY!

[@eliasvor]

did you pass?

[@takuz7879]

@@eliasvor yeah 🙌

[@derricknjoroge2494]

You have the best python OOP tutorials. Thank you, you are helping alot of people especially aspiring developers from Africa. Cheers

[@coreyms]

That's great to hear! Glad you found it helpful!

[@jeremyokuto9856]

Actually from the same country bro

[@charlesdeleau3086]

This is so good that I'm starting to doubt whether all his 'mistakes' are secretly ways to make us learn faster :P

[@wonderoverload0]

Who needs a Udemy course when you have Corey on KZbin. Thanks buddy for making internet useful for us.

[@engee_346]

The sleepless hours that I spent trying understand the nomenclature and the functions that he just made clear in 11 minutes... if you had an advanced professional class that cost money, I would pay for it.

[@peti826]

I know there loads of comments appreciating your work already, but man.. . I started learning python about 1,5 months ago and I have never learnt about OOP, not even its concept and the difference related to other types (still dunno them properly), yet I fully understood everything you said in both of your videos so far... Hats off dude.

[@thuggfrogg]

These videos are insanely good... Definitely not for a 100% noob but absolutely amazing for somebody who's hacked around and now needs a technical understanding to get to the next level. Thanks, Corey!

[@ravenjs]

I'm so so so glad that I found Corey on KZbin. His teachings are state of the art! Whenever there's something I'm confused about python, he is the first person that comes in mind. I'm so very grateful to have you as a teacher, you rock at it! Keep it up! Can't wait for more!

[@coreyms]

Thanks! Glad to have you

[@taofeekajibade]

So, 5 years ago, this amazing video was made and I'm just seeing it in 2022! What a classic teaching it is! Thank you for the supremely brilliant delivery 👍

[@jaxwylde2139]

Wow! Learned more about classes and class variables, in the last 10 minutes, than on a full day going through online python CBT. Can't wait to watch the rest of this series.

[@willylukwago6051]

I don't know why you don't have more subscribers by now, or maybe there aren't many coders out there. But I was afraid of starting learning Python until I stumbled onto this Chanel. Now I can code as a charm.

[@sunnybeta_]

you helped me get an internship. :*

[@coreyms]

Congratulations!

[@Asterite]

@@robbyz512 for experience and understanding , thats simple even tho i wasnt in any internship :p you are basically learning how to work in that level

[@Asterite]

@@robbyz512 i think you are paid man not like alot but still

[@Asterite]

@Berke Icel oh still also a good way for experience :3

[@nomadfox9290]

@Berke Icel That's not entirely true (not being payed for internships). I actually was paid for an internship I did before I was hired on after it was over. I know for a fact the big companies like Facebook, Microsoft, Google, Twitter, etc. pay interns via an educational stipend.

[@kmwrites7456]

Senior here and taking a different online course just to keep the synapses working. Well, you have it way over them in teaching quality. Wish I had seen you first. Thank you.

[@mrchatterjee_]

After working in the industry for 5 years, learned this concept today, just because of the way you made it. I am moving towards into a more coding technology and your videos are gold! Amazing!

[@shiggigigi]

Really? 5 years of tech support scams, and yet you don't know any basics of OOP. Now that's some top tier career dreams

[@Rum8146]

Mind blown..!!! 20+ years ago I was working with Macromedia (Macromind) Director and as a visual designer without coding knowledge or experience I struggled to master Lingo. Over time I ended up at the level of an OOP Lingo coder, albeit one relying heavily on copied code segments and fiercely treasure code examples that I'd gotten to work. FF 20 years and I've returned to coding in the form of Python. SUDDENLY with your videos a window has opened on the murky interior I previously inhabited. I now understand the concepts that you are talking about rather than piecing together code samples. ALL of your videos that I have worked through have been enlightening, fun and edifying. Thank you so much for giving all of this.

[@Soljarag5]

hands down the best OOP tutorial series... I've been using python for 2 years, but have been intimidated by Classes.... this has helped a ton!!!!!

[@anamariabalaban]

It's great that there are people with pedagogical grace, but it's really wonderful when they share their knowledge with beginners. Please don't stop what you're doing ❤

[@Tazumm]

I've seen several sites, books, and videos that all used the Employee class as an example for OOP, however this is the only one that actually made sense and helped me understand the concepts. Thanks!

[@anand29091987]

This is just pure gold. That's how any teacher should be , who makes their student eager to learn more in most simplistic way. Great work Corey.

[@vaclavvlcek4527]

Hi, I need to say your videos are really clear, comprehensive, enough detailed but not boring and too long on the other hand. I just sent you some small donate right now as appreciation. I wish I discovered your channel sooner. Thank you for all your effort!

[@RyanGrissett]

I know most of the other comments have expressed the same feelings a year or two before me, but these are the best tutorials for object oriented programming in python that I've found. It 100% cleared things up for me. I feel like I can finally move on!

[@Kaysler]

This. absolutely blown away in the difference of these tutorials. He has a gift to teach.

[@rsmrostov]

I read a ton of explanation for class attributes and instance attributes, but you explain it so clearly. Great job!

[@SourabhDesaiBrief]

What I love about these lecture, that Errors are explained, which is more intuitive. Thanks Corey :)

[@hashtaggamer1850]

Your pretty much the only thing and/or person who explains any of this clearly

[@RobinIsBetterThanYou]

Just want to say thank you for these videos. I took the wrong path in my education before realising that programming was my true passion. Unfortunately its really difficult to self-teach something like this because of the sheer wealth of information avaliable online. Your videos cover almost everything I've wanted to learn so far, and not only that you don't just 'show' you actually teach. Every time i find myself asking a question about something you've just said, you immediately address why it and explain why it may be confusing. Thank you so much for putting in the time to do this and make it free, you are really making a difference to peoples lives.

[@chenlily9444]

As a beginner, I was stuck with learning Python Class and so lucky to find these videos via Google search! Very informative and easy to understand. BTW, the teacher in these videos also has a nice voice ☺

[@hamdiakkob7925]

Amazing!! So far I'm understanding this giant leap with some ease. 8 years later and you're still helping people out. Thank you man, I felt hopeless really and it was like I hit a wall, but you explain it very smoothly. I did some practice along with your videos and had AI to help me with the vocabulary a little bit, but so far so good. I had to rewind the video every now and then cause you talk too fast lol. English is not my first language so it's my fault. But overall AMAZING man, you got a sub!

[@alessanderboy]

Hello Corey, I'd like to thank you for all the courses on Python you've made. They're way better than udemy courses and any others. You're doing a great job, captain!

[@dragonz369]

As a CS person myself, I’ve seen numerous tutorial videos. Yours is the most logical, right to the point, and easy to understand. 👍 Hope you’ll create more contents.

[@firesidestoryteller]

I've been watching several python training videos. Corey explains things more simply and more completely than anything I have watched so far. Good work.

[@coreyms]

Thanks! Glad it helped!

[@alexanderskae5720]

I have been searching for good tutorials on Python for years, and this series is by far is the most informative. Thank you!

[@carljason4299]

On the 2nd of Feb 2020 ,this video had a 99.64% like - dislike ratio. That's insane. It stands as a testimony to the insanely great work Corey's been doing. Thank you!

[@MrAverageViewer]

Corey, your videos are EXEMPLARY :) Your approach to teaching, and examples you use (e.g. Employees), have finally unlocked the hard-to-understand concepts into easier-to-understand analogies. Thank you for posting these videos!

[@charlesbovalis6591]

I have NOTHING BUT PRAISES for your style, clarity, and to the point explanation of VERY IMPORTANT concepts .... I cannot thank you enough Corey .. I will gladly contribute to your classes and start filling all the "gaps" of knowledge I need to .. You have a devoted student now :)

[@belayz.8246]

I first started watching these videos to help my son, who is currently taking coding courses. I found your videos very very helpful. Thanks a lot, Corey..

[@colinsmith5972]

Corey your explanation of "Class" is just that...... CLASS. Perfect explanation!!! Total Respect.

[@nomoreospf]

Best Python OOP lessons for beginners!

[@vuyokazimatomela6776]

This is the best Video ever to explain classes, i have been very lost for a month trying to get this concept and you explained it in less than an hour thank you soo much. I am going to nail my computer science paper tomorrow

[@falconspy1668]

The best python OOP tutorial on KZbin. Thank you sir

[@Bartnick81]

Quality tutorial! You got my patreon backing.

[@sudarsandm]

Going through your videos we feel like we have covered the most. What we can gain by going through multiple books you walk us through it in one video. Thank you Corey from the bottom of my heart.

[@humayunkabir7925]

I was thinking i am very good in OOP since got i A+(4.0) in the course both in Theory & Lab, somehow i came to the playlist & saw pretty amazing comments, so i got interest to see what's inside. i was thinking myself a pro in OOP. But the way you teach things here are amazing.

[@gauravluitel1344]

i am a beginner to python, on searching many videos in youtube i found your bunch of videos. so nice and so easy to learn, very interactive and you have pointed out every small and basic things. thank you so much.

[@unknown_f2794]

I get more explanations from your videos than what I have got from all of my courses, great work!!!!!!

[@TahmidulAzomSany]

You start with messing up the things, then collaborate them and make a great sense. Awesome.

[@madmowgli1055]

Absolutely freaking awesome. Hands down, you're providing me an A+ headstart for my bachelor course in economy informatics. Huge thumbs up for spreading absolutely logic and understandable explanations. You're amazing. Thanks.

[@Di0n-0]

This is so .... good I am so lucky to stumble up on this. I bought a udemy course and it got me nowhere in 6 hours . I just watched 24-30 minutes of this and I totally get it now . Thank you so much you are an amazing guy

[@hectorserrano9314]

Showing the namespace was so clever to help us thoroughly understand it. Thank you so very much!

[@pratikkawalgikar4839]

Your videos should be at top in the youtube search for "python". I'm recommending your channel to all my friends interested in Python. Thanks Corey. You are a great teacher.

[@noamanrasul]

Oh My God. I was struggling with OOP concepts. Corey made it so simple. Corey keep on doing what you doing my good friend. Thank you.

[@abhiseksahu4455]

Bow down to the maestro...the way you teach is still the best after 5 years of this video...I have been to lots of tutorials for python but always missing the concept...you made it like a butter in the frying pan...it just slips through your mind and I feel satisfied after learning from your videos.... please don't stop your videos...the world needs teacher like you ... #respect

[@cairink2110]

your videos are much better compared to many online courses and free too

[@divutiful]

Posted 4 years back but still, I did not find any other tutorial as clear as these classes one. I have just started learning python and I really appreciate you making these videos. You are an awesome teacher.

[@VishalMishra-hz4fy]

This is the most logical approach to class and objects, i am really glad i found you Sir! Thankyou for such a beautiful explanation. You solved every doubt!

[@harshinivbhat7817]

These are the best videos ever . I struggled to make sense of these concepts before . Now its all so damn logical and intresrting. A Million tonnes of gratitude to u !

[@Finn-jp6pn]

You, sentdex, Traversy Media are the teachers we all need in Uni but don't have. The day I get a job, I'll definitely support you. Thank you for sharing your knowledge.

[@casurajkar7814]

Being from a non-technical background, I was struggling to understand the OOP. But now the concept is clear to me. Thank You..

[@starplatinumrqm]

can't express how nice and easy to understand these videos are

[@harshhes]

OOPs tutorial couldn't have been more better than this.Respect from india, Mr.schafer.

[@stevenshelby2675]

This is the type of youtuber whom I would gladly watch 10 straight ads on their video

[@entropyz5242]

You helped me finally understand object oriented programming in just one video after hours of surfing the web without any result.

[@nadik4531]

Lol your explanations are better than all my professors. How did I not find this channel years ago smh

[@joeymatthews4112]

You are so thorough! I agree with others that you are a natural teacher. The pace, tone, comprehensiveness, and genuine enthusiasm are all spot-on. You are an asset! Thank you!

[@elmastermaestr]

Tank you for covering all of this. I'm truly becoming better in Python because of this

[@kareemjeiroudi1964]

What I loved about these tutorials is that he tried to cover those tricky questions such as instance namespace and class namespace ever for people that are already familiar with these concepts. Keep making videos. Your content is great!

[@datasciencehelp2030]

1 hour of my Grad class summed up in 11 minutes. Thank you!

[@josefh8782]

Probably the best videos Ive been able to find for beginner Python. So articulate and logical in the way you teach, it's awesome. Thanks.

[@thenode_]

Corey, to repeat the sentiment here, you really helped drive home what Object Oriented Programming almost instantly. You should have your own Coursera courses.

[@yassinjulian8418]

I could cry. I wrote a program that needed to automaticly create Buttons and I sat down there for like 5 hours to do this but now I can easily make the same program in 5 minutes and a third of the code. Thank you so much!!

[@mohamedkhodary7831]

Finding your channel is like finding a Gold mine Corey , keep up the Gold work ; - )

[@RubiconDota]

I tried watching these videos several months ago... all went over my head. Now the lightbulbs just keep popping!!

[@mylo5034]

These are really good as i am 12 yrs old and just practising for my class. PS. Keep up the good work :D

[@HaileeMiu]

What middle school class teaches python?

[@aliassem859]

@@HaileeMiu I am 12 years too, but I just learn it for fun, we dont learn it there

[@serpent2776]

@@HaileeMiu Maybe class from outside school?

[@oyuncubirlii]

Hello im a highschooler from Turkey and i loved your series it really tought me a lot about oop and how it works. I really want to add Turkish subtitles to your series and help Turkish students like me to understand this concept easier. Thank You. To enable community contributions: 1- Sign in to KZbin Studio. 2- From the left menu, select Subtitles. 3- From the top, select Community. 4- Select Turn on

[@iuliapintrijal8041]

Best KZbin channel there is! Bravo!

[@evanrudibaugh8772]

This tutorial is so well structured. You immediately answer the sort of natural questions that come up. This subject feels entirely natural and logical to me now. Thanks!!

[@coreyms]

Thanks! Glad it helped

[@simonclaeys1414]

This is so much better than my lectures and book, thank you so much!

[@albertlu9448]

I always had difficulties understanding Python class well, until I found this video that makes it so intuitive.

[@abbyaaguilar]

Dude!!! Such a good explanation. I have a final on Monday and did not understand anything because my teacher thinks he's teaching us by providing us labs with errors and making us figure out how to make it run... How are we supposed to solve it if we don't know WTF Thank you!

[@coreyms]

Glad you found it helpful!

[@davidmiricho385]

The best Python tutorials I have come across. Your explanation is just awesome. Keep up the good work.

[@IonBeamXXIV]

Thank you so much for this series, these videos are fantastic, I feel like every possible pitfall or misunderstanding one could have you articulately and expertly explain.

[@phamvantho4981]

Don't know how to express how grateful I am to have all these materials. Thank you a lot Corey.

[@juderadford5645]

I've been using Sololearn, but this is more straightforward and easy to understand. Thanks!

[@kwiatriot6190]

I am using Sololearn as well and Corey is way better at the OPP stuff!

[@AnweshDash]

In 2022 and finally I'm able to get this conceptually clear after watching so many other videos this really did the trick for me, thank you so much

[@aditimore3967]

You might have no idea how helpful this was to us.

[@xolanigumbi8951]

To me classes have been the hardest part of Python to learn - but from what I've watched so far, I think I kind of get the idea. Thank You!

[@SagnikDuttaegor92]

Who gives dislikes for gems like these??? For now I only have love and respect for you Corey, Patreon to follow soon :)

[@inomad.djibouti]

i have gone through many learning video but because of your video, i became fan of python.coding language. a big thumb to you and keep posting and share your knowledge with everyone ,thank you very much..

[@gavravdhongadi9824]

You are literally giving me hope, appreciate it

[@jh6643]

One of the best OOP tutorials on YT.

[@Abbekej]

You are next level, man. Respect!

[@jeffreyhymas6803]

These videos are amazing, thank you. Clear, concise, and informative. I'm paying 7 grand a year to go university for Computer Engineering and I've learned more in two of your videos then I have in my programming class all semester.

[@t07minas]

7 grand ? Wtf I should be more thankful to german education system i guess

[@jeffreyhymas6803]

Yeah, and that's on the cheap end since I go to a state school. Private schools would be several times that. Yay for being American

[@jeangtr]

You, my friend. You are a life saver. Keep up the excellent work! Lives being changed because of you :D

[@kannanv8831]

Every tiny details are explained in well manner. I am glad to get a teacher like you.

[@Wu_wu_wu6]

Everything is so well placed and informative, thank you!

[@yeetyeet4321]

You are highly underrated you come off as interesting and you put the rest of the videos in your description. Subscribed