Inheritance Example

Thanks. Well paced and a nicely gentle introduction to OOP. At least it is gentle if you already have the basic concepts and are treating this as a refresher :-)

Great videos. I found my understanding of OOP was really solidified when working with SQLAlchemy for a Flask project, and having Post and User classes.

Will you be doing a follow-up series which delves into multiple inheritance, encapsulation and polymorphism? I hope you do! Good job on the intro to OOP :)

Very good intro to OOP in python.

Very good intro even for a complete beginner. Sweet and to the point !

This was well presented and helpfu. Thanks!

Really good introductions, i got all the concepts, its easy to follow. Thanks.

Very good introduction!

excellent intro.

I would love to see another series of videos that explains the next level of complexity. How about a series explaining some of the fundamental ‘dunder’ methods? Videos were clear and concise. very … pythonic.

Very good - thanks! I’ve been using classes without really having a good understanding of them. This course helped a great deal.

Good one…can you please cover session 2 on Abstraction, encapsulation and polymorphism and some advance topics on OOPs. Thank you.

Very good videos. I started learning the concepts of OOP programming at university, but I needed a more visual way to understand the concepts. Thanks!

Nice series of tutorials, great pace and clarity.

Thank you so much, really helpful for beginners.

Great course, clear and concise, with poignant examples! 10/10 honestly, wouldn’t know what to improve

Indeed a superb explanation .

Awesome intro!

Very easy to follow. Keep up the great work.

Thanks for this. I so much love this.

Very neat and simplified,thanks

5 stars

finally I understood classes

Despite some nitpicking on mental example context switching and some assumptions made in explanations, this was a better tutorial than most for general consumption on youtube!

Yes, would definitely like to see expanded OOP tutorials moving forwards, in particular passing data dynamically into objects.

really good…tks for the great content

Nice introduction to OOPS

Awesome, I like your enthusiasm

Hi @Austin Cepalia, since class Baby inherit class Person. Why init(self) doesn’t show result to Child class same as Parent class?

>>> I am Steve and 7 years old. # class Person
>>> I am Ian and 1 years old. # class Baby(Person)

Thanks for the video tutorial, I get already the concept and need to practice more about OOP.

I have been trying to understand OOP for a while and this is the first tutorial in which I’ve started feeling I know what is all about! Thanks!

Thanks!

I am trying to write a class that takes in an instance of another class in the constructor method. For context, here is how I am trying to do this:

class Family: def init(self, lastname, member_count, hair_color): self.lastname = lastname self.member_count = member_count self.hair_color = hair_color

class Person(Family): def init(self, Family(lastname, member_count, hair_color), name, gender, age): self.name = name self.gender = gender self.age = age self.Family() = Family()

I am getting an invalid syntax error pointed towards my Family instance variable in by Person constructor. How can I effectively pass in instance of a class as a constructor variable in another class?

Shoot, my code did not come in well. Here it is:

class Family:
    def __init__(self, lastname, member_count, hair_color):
        self.lastname = lastname
        self.member_count = member_count
        self.hair_color = hair_color

class Person(Family):
    def __init__(self, Family(lastname, member_count, hair_color), name, gender, age):
        self.Family() = Family()
        self.name = name
        self.gender = gender
        self.age = age

Thanks, Excellent introduction.

Excellent!! Crisp and simplistic way of explaining the most confusing terminologies

excellent stuff, thank you sir!

Its great how you picture parent and child class. Baby needs a nap(), brilliant! (: Well explained

Yes inhertance finally understood thank you

This was very helpful, thanks

Excellent!

Thank You - this cleared up some basic understanding for me.

Excellent presentation with simple examples.

That was amazing introduction to OOP. Thanks 👍

Great video, it truly helps with my understanding! ^^ Thanks !

Great intro. I need to start designing classes for the project I am working on so it was good to get a quick intro. I would like to see more advanced topics discussed at some point.

Awasome tutorial on OOP

excellent.. can we get the slides of this topic(download)

Thank you for this series. I helped job my memory and review the concepts.

Very well done. I wish I had this back when I was in school.

Great explanation! Helped me to grasp the idea of inheritance.

This was just what I needed to solidify my understanding of OOP. As a new programmer it seemed so abstract and complicated, but here it was simple. Thanks!

Finally, I found a course which explained me OOP.

Excellent speaking voice and content presentation! Quite motivated now to move ahead with Object Oriented Programming. Apparently very versatile in building applications and website construction. :)

Neat

Well done! The best intro, by far, I have found on OOP. Even better than the one I got from Univ of Michigan’s online class. You are the hard to find very good programming teacher.

I finally see the light!

@acquatellamax That’s how I felt too :)

Good Job!!

Very well explained; thumbs up!

Thanks Austin. Very well explained.

Thanks, great videos. Very clear to help understand “DRY” and “overwriting” in inheritance. I am wondering whether Python have the concept of interface or abstract classes like Java? So that the it can just define the behaviour of a particular set of methods, that child class must implement. If we want to create new classes that have behaviours of multiple parent class or “interface”, what is the way of doing this.

Can you please explain why baby is not an instance of person in below example:

class person:
    description = "general person"

    def __init__(self, name, age):
        self.name = name
        self.age = age

    def speak(self):
        print ("My name is {} and Im {} years old".format(self.name,self.age))

    def eat(self,food):
        print ("{} eats {}".format(self.name,food))

    def action(self):
        print ("{} jumps".format(self.name))


class baby(person):
    description = "Baby"

    def speak(self):
        print ("bla bla bla")

    def nap(self):
        print ("{} naps".format(self.name))

p = person("Saat",8)
p.speak()
p.eat("Pizza")
p.action()
b = baby("Sammu",1)
b.speak()
b.eat("baby food")
b.action()
b.nap()
print(isinstance(baby, person))

Output:

My name is Saat and Im 8 years old
Saat eats Pizza
Saat jumps
bla bla bla
Sammu eats baby food
Sammu jumps
Sammu naps
False

@sangeeth2kin The word instance is synonymous with an object. The isinstance() function can tell you whether a given object is an instance of a particular class:

>>> isinstance(b, person)
True

To check if two classes belong to the same hierarchy, you want to use the issubclass() function instead:

>>> issubclass(baby, person)
True

To avoid this confusion, people generally follow a naming convention, which uses PascalCase for class names and snake_case for their instances or objects:

class Person:
    pass

person = Person()

Got it, thank you.

This was a fantastic intro to OOP! The step-by-step process and clear instruction helped me understand concepts I couldn’t before. One topic that was especially difficult for me was the use of the ‘self’ parameter and the ‘initializer.’ This video tutorial clarified those features of OOP and made it easy for me to use them. I’m excited to build on this knowledge with the other OOP video tutorials at RealPython!! Thanks, Austin!

Wow, great intro to OOP. Finally got it.

This was really nice Tutorial. My understanding of OOP is getting better now.

Hi all! I’m new here and for sure me a member was the best thing that I did to keep myself on Python Learn track! All videos, articles and stuffs on this website are amazing! Topics are well explained, lean samples and directly to the point. Nice tutorial!

Great tutorial, I watched it several times and kept coming back for clarity. Within days I wrote two classes/modules and had them running. The concepts, especially the architecture framework, are well explained. This helped me finally get into OOP, Thanks

Great, clear explanation. Overriding is mentioned, is this different that overloading? Does Python support method overloading?

@ljob Overloading is about having a couple of functions with the same name but different signatures. There is no concept of function overloading in Python, particularly method overloading. You cannot have several functions defined with the same name and different implementations in one lexical scope.

It’s not a syntax error, though. The last function definition will simply overwrite all previous ones with the same name because Python treats namespaces like dictionaries. And, a dictionary cannot have duplicate keys.

Instead of creating many different functions, you might take advantage of the default parameter values to simulate function overloading. Alternatively, you can take a look at the @singledispatch decorator in the standard library or a more versatile third-party @multipledispatch one.

Thank you for the clarification!

What if you were going to create several persons? would it be best to do like this:

person1 = Person("steve", 20)
person2 = Person("charles", 18)

or like this:

steve = Person("steve", 20)
charles = Person("charles", 18)

@gilpinbmchs Descriptive variable names such as steve and charles are preferable. If you wanted to spawn arbitrary number of Person instances, then you could use a list or a list comprehension:

# list (could be another sequence type like a tuple)
users = [
    Person("steve", 20),
    Person("charles", 18)
]

# list comprehension
users = [Person("some_name", i) for i in range(2)]

ok thanks. now I’m going to explore list comprehension, thanks!

nice topic

Good stuff - I am new to Python but I have good experience in C++ - for me it was all about how to create Python class and method in Python and it was well said - it was easy learning for me because of the experience I have in C++ programming language.

Probably one of the best introductions to classes I have seen.

Thank you so much for this great tutorial session. Very well explained for novices like me to get a grasp of the concepts and the usage as well in the initial stages.

This was great but left me hungry for the next level(s)! Could you please add lessons on the other important topics in OOP?

@anaghost Sure! What what topics would you be most interested in?

Thank you, Bartosz! A few people before me mentioned multiple inheritance, encapsulation and polymorphism. For me, personally, it would be very beneficial to see a more complex real world example of OOP use. Basically, how an SDE thinks when using OOP for a real world application, not just a Dog class. That would be great!

This course gave a gentle introduction to OOP, loved the way it was clear, concise and straightforward not beating around the bush, highly recommended for beginners. Thanks Austin, you’re awesome.

Thanks for this very clear explanation!

Very good introduction! Thank you!

Great intro/refresher to OOP. Thanks!

Though an introductory course, it could still demostrate some classes implementation from real world situations, instead of Dog and Person classes.

Extensive exercise on every topic can help retaining everything in mind.

Thank you for this excellent course!! clear and thorough understanding..

This was a short but clear explanation of how OOP works. Thanks, Austin, for sharing all this knowledge. This introduction was brief, and there is much more to cover, but now we have a solid foundation to move forward.

Very good into to OOP in Python. Is it planned to extend the course with dataclasses?

Suggestion : The quiz should come at the very last of the course but its coming before the last topic i.e. Inheritance Example and Course conclusion

@martandgupta93 thanks for flagging it, the course had previously combined the last content lesson with the summary, so the quiz placement didn’t make sense in the second-to-last spot. We now split the final lesson into two, so now the quiz comes after you’ve gone through all the content :)