Video timeline! 1:34 - Why use classes? 2:27 - Defining our first class in Python 6:05 - Class methods 13:53 - Passing in default keyword arguments (size of our polygons) 20:18 - Inheritance & subclassing (using the super() method) 24:43 - Class method overriding 26:06 - Plotting points with classes 28:09 - Operator overloading Thanks for watching! Please consider liking & subscribing if you enjoyed this video :).
My experience with all computer programming, 40 years of experience, starting with Fortran, then C++, Java, LaTeX & TeX typesetting, and now Python, is that it is such a colossal waste of effort. To spend 40 years trying to figure out the meaning of one piece of syntax, and then succeeding, only to have never made any money during those 40 years because all one did was try to figure out what that one piece of syntax does or means, is the understatement of understatements of Pyrrhic Victory. I honestly now hate it more and learn and understand less of it now than at any earlier point in my life. At least taking formal community college courses got me to understand and do something with programming. But literally there exists absolutely nothing PRACTICAL that one can do with computer programming in ANY language outside doing formal college course work for a teacher. I mean, sure, just to make the codehead morons & idiots happy whose entire life is wrapped up in fetishizing and worshipping and oohing and aahing at one language using a period and another language using a ? mark to delimit a command or whatever, believe it's the greatest thing since farming & anesthesia when I figure out how to get one line to work, before getting stopped for the next 10 years by the next 200 lines of code. To teach me programming, you would have to personally live with me and work with me every day for 10 years, and pay me $30,000 a year to do this thing I hate. Best to stick to proving mathematical theorems. At least, when one finally triumphs after 30 years trying to solve that, one has added new deep original knowledge to the collective knowledge of humans.
I’ve just returned to programming. I grew up in the 1970s/80s programming an old TRS-80 in basic. I’ve just started learning Python and have been struggling with classes, so, thank you. Your video and style of teaching was excellent and I finally think I can understand now.
For angles, we can use simple formula, exterior angle for n sided polygon = 360/n, and in draw method, we can use left instead of right as below. turtle.forward(self.size) turtle. left(360/self.sides) We can get the polygon drawn
Yes, this! When I took a Python class my first year at my university, they used this method to draw pentagons with the turtle package. I realized in class that this method was not only very intuitive, but also could be used for what became my favorite derivation for the interior angle formula of a regular n-gon (or by extension, their sum formula).
I've always struggled to understand the usefulness of classes, and this video communicated it really well with great examples. Thanks for always producing quality content!
I had lots of trouble understanding classes. I watched no less than 5 videos and went through many sites and this video really helped me to understand. Great job!
After learning Python via SoloLearn and having to struggle through their horribly designed lesson on OOP for Python, this tutorial was an amazing help at actually understanding OOP.
These days when I am looking for a lesson, I always have to include in the search '...by keith' and even if don't TH-cam brings your videos first because they know my preference!. Such a great teacher, I have followed through many of your lessons decided to shout out on this one. Keep being on fire.
You are "my kind" of teacher. Going forward in a relaxed nice progressive way. You being a graduate from the best university in the world certainly gives you credibility too, haha. Keep up the good work!
I have built a couple of basic classes but I’m writing one to auto do a bunch of freq calcs that is a lot more complicated. 10min into your vid and I finally got a work in progress. Thank you!
This was really handy! Between a 5 hour "Nana" Python tutorial I watched earlier and this, I have a greater understanding of OOP than I have had for the past 15 years of off-and-on reading of programming books trying to grasp it.
Man, you're saving my days! I want to make a snake game in python and saw some tutorials on the ytb and found nothing that i could totally understand. Then I saw you Python Game Tutorial and learned so much! Besides that, I saw you GUI tutorial and learned so uch about Tkinter too. So, thank you so much and continue doing this awesome job! Regards from Brazil
I usually see examples of people who use the Name, age class. This one is much better because you actually do one that's much harder but you explain it so well. Thank you so much for this video.
First thing I have had difficulty with in Python. Was pumped to find out I can have my buddy from high school teaching it to me haha really helpful video man!
Hahaha what's good Trevor! I definitely found classes confusing at first too. Happy that you stumbled on this video and found it helpful! Hope all is well :).
Great video! To elaborate on some previous comments that suggested 360/n: The reason this works is that you are using the EXTERIOR angles in turtle geometry, and the exterior angles of any regular polygon always add to 360. This is the classic "Turtle Trip Theorem"
Hey Keith! Amazing video. I found this video because I wanted to truly understand the basics of classes and you did such a great job of explaining it in a simplistic way. Not to mention showing off some cool visual libraries! Looking forward to see what other videos you have.
One small correction. At 6:30 (and at at least one other spot) you talk about a "class method" and say this it should have a parameter "self." Although it is defined within a class, this is in fact an "instance method." Instance methods have a parameter "self." Class methods do not.
Yeah, this is an unfortunate oversight in an otherwise great video. It wouldn't be so bad if this were another way to say the same thing, like "argument" and "parameter." But a class method (@classmethod) is actually a different thing, so it will actually lead to confusion later on.
This is a really good video for beginners in python. Just a small suggestion, instead of using any complicated formula for interior angles of a polygon, just divide 360 by number of sides of the polygon and you will get the interior angle. No need to make the formula complex.
Well chosen example and leaving some things for later and picking them up at an appropriate point in time like "self". Going into enough details but not to much, i.e. simplified enough (substituting "+") to get the idea, but not to a point where the statement actually isn't correct (e.g. common with metaphors), thus only confusing (smarter) people. Thanks for the effort!
one thing i like to point out when explaining "self", python does the following: when you define a class, you define functions that look like Polygon.draw, and you can call those functions as Polygon.draw(square), for example, once you've made a square. As a shorthand, python allows you to move the object to the front in place of the class name, hence square.draw()
the utility of this is usually in cases of multiple inheritance if you want to call a specific parent class's method instead of all super classes' versions of that method at once.
Regarding the polygon example instead of: defining Object properties self.interiorAngles = (self.sides - 2)*180 self.angle = self.interiorAngles/self.sides and then using them with turtle.right(180-self.angle), you could just use: turtle.right(360/self.sides) because every polygon has an angle sum of 360º and you want all of your polygon's angles to be equal in each of your sides.
We are learning classes in my programming 1 class and not even our textbook (by person) goes over how to make our modules useful. Our book has been a nightmare our entire semester. Luckily our professor doesn't teach straight from the textbook and luckily I found your video on youtube.
I usually think of the 'self' argument as a reference to an initialized object. We could have 37,493 uniquely named Polygon() objects that have been initialized into memory (ie: we made poly1 = Polygon(params), poly2 = Polygon(params), poly3 ... etc ... 37,493 times. Each one of these objects has a unique value for 'self' that Python is using to be able to find the memory location of the particular instance of Polygon() you are interested in using/manipulating.
I couldn't figure out how to contact you directly. But could you please make another video on classes? One that shows them in use in a program? This video was the first time that I started to understand why I should use classes. I need to see them being used in real world examples of code though. Please man, you're a great teacher.
Such great tutorials! Really great teaching style and great examples! It is really fun watching and learning. Felt so proud when i noticed the missing "self" before you did :D Great accidental attention check :-)
I watched this episode for the first time, so I can understand the object-oriented approach Really thank you very much The only thing I still don’t know much about the usage of __add__, the others are generally understood Student from Taiwan
When would you maybe want to define the arguments inside the draw method within the class? e.g. def draw(self, size, color). In this example, this would've worked, right?
Hi Keith Galli, Your tutorials are simply awesome. I have enjoyed every bit of it. Will it be possible for you to make a small video on polymorphism, encapsulation, multiple inheritance and context manager. PS: the introduction of Glasses..oops..classes...classes in Python was the cherry on the cake.
Would be nice to see some practical use of classes in data science (data visualization). Or maybe you know where can I find examples? Keep up good work!
My attempts to import matplotlib.pyplot as plt fail. I have installed and imported matplotlib, but cannot install matplotlib.pyplot. pip install pyplot generates the errors: ERROR: Could not find a version that satisfies the requirement pyplot (from versions: none) ERROR: No matching distribution found for pyplot I'm using PyCharm on Win10, but I get the exact same errors when running from the Cmd line. Any suggestions?
😊😊 you nailed it 💯 and best content ever bro. And the glasses at first you got me I thought you gonna teach about blue ray lenses then you came back on track 😂😂😂, but for the video you did great keep it up
Video timeline!
1:34 - Why use classes?
2:27 - Defining our first class in Python
6:05 - Class methods
13:53 - Passing in default keyword arguments (size of our polygons)
20:18 - Inheritance & subclassing (using the super() method)
24:43 - Class method overriding
26:06 - Plotting points with classes
28:09 - Operator overloading
Thanks for watching! Please consider liking & subscribing if you enjoyed this video :).
My experience with all computer programming, 40 years of experience, starting with Fortran, then C++, Java, LaTeX & TeX typesetting, and now Python, is that it is such a colossal waste of effort. To spend 40 years trying to figure out the meaning of one piece of syntax, and then succeeding, only to have never made any money during those 40 years because all one did was try to figure out what that one piece of syntax does or means, is the understatement of understatements of Pyrrhic Victory. I honestly now hate it more and learn and understand less of it now than at any earlier point in my life. At least taking formal community college courses got me to understand and do something with programming. But literally there exists absolutely nothing PRACTICAL that one can do with computer programming in ANY language outside doing formal college course work for a teacher. I mean, sure, just to make the codehead morons & idiots happy whose entire life is wrapped up in fetishizing and worshipping and oohing and aahing at one language using a period and another language using a ? mark to delimit a command or whatever, believe it's the greatest thing since farming & anesthesia when I figure out how to get one line to work, before getting stopped for the next 10 years by the next 200 lines of code.
To teach me programming, you would have to personally live with me and work with me every day for 10 years,
and pay me $30,000 a year to do this thing I hate. Best to stick to proving mathematical theorems. At least, when one finally triumphs after 30 years trying to solve that, one has added new deep original knowledge to the collective knowledge of humans.
If you want to add more points at once, use the __radd__ function.
I’ve just returned to programming. I grew up in the 1970s/80s programming an old TRS-80 in basic. I’ve just started learning Python and have been struggling with classes, so, thank you. Your video and style of teaching was excellent and I finally think I can understand now.
For angles, we can use simple formula, exterior angle for n sided polygon = 360/n, and in draw method, we can use left instead of right as below.
turtle.forward(self.size)
turtle. left(360/self.sides)
We can get the polygon drawn
Yes, this! When I took a Python class my first year at my university, they used this method to draw pentagons with the turtle package. I realized in class that this method was not only very intuitive, but also could be used for what became my favorite derivation for the interior angle formula of a regular n-gon (or by extension, their sum formula).
I've always struggled to understand the usefulness of classes, and this video communicated it really well with great examples. Thanks for always producing quality content!
I had lots of trouble understanding classes. I watched no less than 5 videos and went through many sites and this video really helped me to understand. Great job!
After learning Python via SoloLearn and having to struggle through their horribly designed lesson on OOP for Python, this tutorial was an amazing help at actually understanding OOP.
Sololearn is a really good free app to learn coding imo also the community is great
These days when I am looking for a lesson, I always have to include in the search '...by keith' and even if don't TH-cam brings your videos first because they know my preference!. Such a great teacher, I have followed through many of your lessons decided to shout out on this one. Keep being on fire.
Great video!
Can you do a 'solving real world data science problem'-video using classes?
You are "my kind" of teacher. Going forward in a relaxed nice progressive way. You being a graduate from the best university in the world certainly gives you credibility too, haha. Keep up the good work!
This is by far the best video I've seen on TH-cam for this topic .Thanks a lot Keith
Glad you enjoyed! :)
I did not understand classes at all until watching this. You did what my university lecturer couldn't. Thanks a bunch!
This channel is underated af . Great work my guy !
I have built a couple of basic classes but I’m writing one to auto do a bunch of freq calcs that is a lot more complicated. 10min into your vid and I finally got a work in progress. Thank you!
This was really handy! Between a 5 hour "Nana" Python tutorial I watched earlier and this, I have a greater understanding of OOP than I have had for the past 15 years of off-and-on reading of programming books trying to grasp it.
One of the best explanations of oop. Thank you! Love the way you get enthusiastic when talking about sub classing around 24' :D So nerdy
Glad you enjoyed! And lol yeah gotta love subclassing 😁
I already knew most of this stuff, but you teach so well that it was really nice watching this video!
This is the best explanation of Python Classes, much much appreciate it.
Man, you're saving my days! I want to make a snake game in python and saw some tutorials on the ytb and found nothing that i could totally understand. Then I saw you Python Game Tutorial and learned so much! Besides that, I saw you GUI tutorial and learned so uch about Tkinter too. So, thank you so much and continue doing this awesome job! Regards from Brazil
This was one of the best videos i have seen on python classes. Thanks a lot for sharing
This was a great video, i finally am starting to understand classes in python because of this video, thank you.
Same here. Thanks!
Dude, this video is great. I learned so much. You're an excellent teacher.
You're a great teacher. Thank you so much :) You'll def. know how classes work in Python after watching this!
This is the best tutorial for classes
i´ve see a lot of videos about this issue in youtube, and your video it´s the best. greetings from spain!! keep going!
oh man, your tutorials are the best I have found!
I usually see examples of people who use the Name, age class. This one is much better because you actually do one that's much harder but you explain it so well. Thank you so much for this video.
My unviersity/college teachers just gave us a debugging assignment with all __init__, subclassing too and I was so confused, this was very helpful
First thing I have had difficulty with in Python. Was pumped to find out I can have my buddy from high school teaching it to me haha really helpful video man!
Hahaha what's good Trevor! I definitely found classes confusing at first too. Happy that you stumbled on this video and found it helpful! Hope all is well :).
i dont have words u just saved me big time bro thank you so much for making this video
print("thank bro")
Explained it better than my professor, yes told him that your videos are better, in my country they don't know how to explain.
Cheers Keith, so good. The polygon example is the best one i've seen as a beginner.
probably the only vid on classes that have made sense of it to me
Great video! To elaborate on some previous comments that suggested 360/n: The reason this works is that you are using the EXTERIOR angles in turtle geometry, and the exterior angles of any regular polygon always add to 360. This is the classic "Turtle Trip Theorem"
choosing to do shapes for visual aid was a great idea this was really helpful !
Very well done! Now it is so beautiful, to see and understand the concept of object programing language. Thank you, Brother.
thankyou for your videos..
I have two video series requests for you :
1) DSA in python
2) Competitive coding with python (if possible)
Hey Keith! Amazing video. I found this video because I wanted to truly understand the basics of classes and you did such a great job of explaining it in a simplistic way. Not to mention showing off some cool visual libraries! Looking forward to see what other videos you have.
This analogy is so much easy to understand what class is.
More helpful than any other tutorial I’ve seen, Thankyou!
Super useful! Very clear and concise explanations throughout. Thanks.
My book taught me basically everything but I didn’t know what any of it meant this video is great for understanding what you’re doing!
21:15 - when you realize you frigged up LOL. Great vid dude!
21:15 small moment of clarity
Amazing video! Thanks Keith! We wait for more of them!
Most helpful video I've seen yet!
One small correction. At 6:30 (and at at least one other spot) you talk about a "class method" and say this it should have a parameter "self." Although it is defined within a class, this is in fact an "instance method." Instance methods have a parameter "self." Class methods do not.
Yeah, this is an unfortunate oversight in an otherwise great video. It wouldn't be so bad if this were another way to say the same thing, like "argument" and "parameter." But a class method (@classmethod) is actually a different thing, so it will actually lead to confusion later on.
Straightforward and clear...great technique you use to demo these concepts...thanks so much from a budding old geezer hobbyist!
Great video and that lo fi jumper is 🔥
Great video! what happened at 21:16. Some debugging there
Thank you Keith, so much helpful
Maybe mention "Setter" and "Getter" Methods in a follow up video?
This video was excellent.
Good suggestion! I'll probably include that in the follow up vid
Thank you Keith, I learned so much in this video. Subscribed
This is a really good video for beginners in python. Just a small suggestion, instead of using any complicated formula for interior angles of a polygon, just divide 360 by number of sides of the polygon and you will get the interior angle. No need to make the formula complex.
Yeah I needed to review my geometry before making this video. Thanks for the suggestion & glad you enjoyed the video 😊
Best Class Tut Ive found yet! Youre a genius. Subscribeb hahaha
Very helpful tutorial and thank you for your time
Wow!! I am appreciated for that explanation of Classes in Python. Very detailed information :)
Well chosen example and leaving some things for later and picking them up at an appropriate point in time like "self". Going into enough details but not to much, i.e. simplified enough (substituting "+") to get the idea, but not to a point where the statement actually isn't correct (e.g. common with metaphors), thus only confusing (smarter) people. Thanks for the effort!
Thank you! Your feedback means a lot :)
awesome content
Thank you!
thank you from Korea! your videos helped me so much
This is an outstanding video. Thanks for taking the time!
u were at MIT!!! What a legend. That's my dream and i'll follow what u did
one thing i like to point out when explaining "self", python does the following:
when you define a class, you define functions that look like Polygon.draw, and you can call those functions as Polygon.draw(square), for example, once you've made a square. As a shorthand, python allows you to move the object to the front in place of the class name, hence square.draw()
the utility of this is usually in cases of multiple inheritance if you want to call a specific parent class's method instead of all super classes' versions of that method at once.
Thank you for this video! I really like the way you explain things.
Fantastic video, thank you for putting this up. Looking forward to watching more.
i love your reaction at 17:32
Regarding the polygon example instead of:
defining Object properties
self.interiorAngles = (self.sides - 2)*180
self.angle = self.interiorAngles/self.sides
and then using them with turtle.right(180-self.angle), you could just use:
turtle.right(360/self.sides)
because every polygon has an angle sum of 360º and you want all of your polygon's angles to be equal in each of your sides.
Excellent video Keith!
We are learning classes in my programming 1 class and not even our textbook (by person) goes over how to make our modules useful. Our book has been a nightmare our entire semester. Luckily our professor doesn't teach straight from the textbook and luckily I found your video on youtube.
I usually think of the 'self' argument as a reference to an initialized object. We could have 37,493 uniquely named Polygon() objects that have been initialized into memory (ie: we made poly1 = Polygon(params), poly2 = Polygon(params), poly3 ... etc ... 37,493 times. Each one of these objects has a unique value for 'self' that Python is using to be able to find the memory location of the particular instance of Polygon() you are interested in using/manipulating.
Thanks for adding this detail! Very useful way to think about it. Hearting this comment so more people can see it! :)
I couldn't figure out how to contact you directly. But could you please make another video on classes? One that shows them in use in a program? This video was the first time that I started to understand why I should use classes. I need to see them being used in real world examples of code though. Please man, you're a great teacher.
Hey i have actually already made a video like that! Check it out here: th-cam.com/video/731LoaZCUjo/w-d-xo.html
Thanks buddy, it was a great video!
Such great tutorials! Really great teaching style and great examples! It is really fun watching and learning. Felt so proud when i noticed the missing "self" before you did :D Great accidental attention check :-)
Glad you enjoy the tutorials! And nice job catching my mistake before I did xD
Great intro to class; thanks!
thumbs up for the beginning :D
I watched this episode for the first time, so I can understand the object-oriented approach
Really thank you very much
The only thing I still don’t know much about the usage of __add__, the others are generally understood
Student from Taiwan
I think you forgot to incorporate a triangle. I think I will try to do it. Thank you for the explanation man..Great.
Superb video on classes.
nice vid! I'm surprised you didn't mention the __str__(self) function as it would have made those print statements easier.
17:32 I'm actually understanding all of this and at this time i was also like oh my god!! why does this happen !!😂
Best I have ever seen
When would you maybe want to define the arguments inside the draw method within the class? e.g. def draw(self, size, color). In this example, this would've worked, right?
great help buddy thanks a lot
Really enjoying your tutorials,
Thank You.... I have learned a lot from your videos
Nice video, thanks for the easy to follow explanations.
Hi Keith Galli, Your tutorials are simply awesome. I have enjoyed every bit of it. Will it be possible for you to make a small video on polymorphism, encapsulation, multiple inheritance and context manager. PS: the introduction of Glasses..oops..classes...classes in Python was the cherry on the cake.
I hit the like button at 0:09 seconds
Thank you for the video, great work. Appreciate your work.
I loved this video, thank you!
You can also do:
angle = 360 / sides
This will give you the same result.
Amazing video. Helpes a lot
Would be nice to see some practical use of classes in data science (data visualization).
Or maybe you know where can I find examples?
Keep up good work!
I agree! Check out my machine learning tutorial, linked to in the description as one example.
What a tutorial, really great. THANKS
Thanks!! Well explained! I had to subscribe and like. :)
Ur intro is cool bro🤣🤣🤣🤣🔥like ur way of teaching
Great tutorials Keith!! Very clear and concise stuff. Grateful if you would do something on Python from A to Z. Regards
Excellent Python teacher 👍👍🌹🌹
Awesome explanation!
My attempts to import matplotlib.pyplot as plt fail.
I have installed and imported matplotlib, but cannot install matplotlib.pyplot.
pip install pyplot
generates the errors:
ERROR: Could not find a version that satisfies the requirement pyplot (from versions: none)
ERROR: No matching distribution found for pyplot
I'm using PyCharm on Win10, but I get the exact same errors when running from the Cmd line.
Any suggestions?
Thanks for the tutorials!
Will you do any content on using Python with Google Docs/Sheets?
😊😊 you nailed it 💯 and best content ever bro. And the glasses at first you got me I thought you gonna teach about blue ray lenses then you came back on track 😂😂😂, but for the video you did great keep it up