What does Python's __init__ method do?

If you are creating a new class in Python, you're probably writing a new _init_ method. But what does _init_ do? And do you really need to write it? In this video, I answer a question from Brett, who has read my book (PythonWorkout....) and subscribes to my newsletter (BetterDevelope....
(And apologies for the cut-off sound at the start of the video!)

[@studentHindes]

Your typing skills are otherworldly. Oh, and I really like your teaching style! Edit: I just subscribed to manning to read your book - what a cool platform

[@ReuvenLerner]

Excellent and thanks on all fronts!

[@smashies118]

This video just prevented me from going down a rabbit hole. Thanks!

[@ReuvenLerner]

Delighted to hear it!

[@safkaify7875]

Nicely explained. Keep up the good work.

[@ReuvenLerner]

My pleasure; glad you enjoyed!

[@basil9633]

Great video ! , videos like this are very informative and help young developers like me.

[@ReuvenLerner]

I'm so glad to hear it helped!

[@o1Lars]

Thanks also for saying "dunder init", as it just helps tons to know the correct wording when talking about code !

[@ReuvenLerner]

Glad it helped!

[@muntadher8087]

Thank you so Much for having the live read online reading, it's useful. I will start reading your book. God bless you! Thank you

[@ReuvenLerner]

I'm delighted to hear you enjoyed it, and hope you like the book, too!

[@Al-lg8nv]

wow, such a concise explanation. Love your typing speed and accuracy!

[@ReuvenLerner]

Thanks so much! The typing speed is all thanks to my father, who forced me to learn to touch type in high school. It was definitely one of the best skills I ever learned.

[@bartosz13]

Thank You for this

[@ReuvenLerner]

Glad it helped!

[@Chapter9]

fan of your code typing speed 😀

[@ReuvenLerner]

Thanks! It's all thanks to my parents, and especially my father.

[@hashimnaushahi]

I really like the way you teach Python! Do you also have a video about the builder pattern, or would you be willing to create one?

[@ReuvenLerner]

Thanks for your kind words! I have a (paid, recorded) course on design patterns, but I don't think that it includes the builder pattern. (It often depends on whether I have time to fit it in.) If not, I'll see if I can do something here on KZbin.

[@hashimnaushahi]

@@ReuvenLerner Thank you! I'll be looking forward to that video. In the meantime, do you have a link to your paid course?

[@ReuvenLerner]

@@hashimnaushahi Absolutely -- the design patterns course is at store.lerner.co.il/design-patterns (which isn't explicitly mentioned yet, but is a free part of my course membership at LernerPython.com). Let me know if you have any further questions!

[@bigbadcatbigbcy2933]

thank you this explained a lot of things to me

[@ReuvenLerner]

I'm so delighted to hear it!

[@crystallewis1198]

Thank you!

[@ReuvenLerner]

My pleasure -- glad it helped!

[@manny4527]

I wish I could type my code like you. I still have to look at the keyboard 😅

[@ReuvenLerner]

Thanks; it's all thanks to my parents! But you can/should also learn to touch type. It's possibly the most practical skill I've ever learned.

[@jacques8290]

Great video, thanks for sharing this.

[@vinkenwood8233]

I didn't get it at all, but great video, thanks.

[@ReuvenLerner]

Thanks! (Feel free to ask if there are things you still don't understand.)

[@SteamTrain2639]

What is the point of the lines that say: self.x = x self.y= y ?

[@ReuvenLerner]

Self is the new instance. Attributes set on self are the Python equivalent of setting instance variables. We thus take the parameter x (whose value was set by the caller) and assign it to self.x, keeping the value around. We then do the same thing with y.

[@excalizan7697]

Great tutorial!

[@kdpr007]

Thank you for the video. Ca you please suggest a good book to read on Classes and Objects. Thank you

[@ReuvenLerner]

I don't know about a book, but I gave two webinars/courses, "Python objects for newbies," that are part of my subscription service at LernerPython.com . And you can check out my video here, which explains some things: kzbin.info/www/bejne/kHWWnH6BZsSXm7M

[@olagarto1917]

but what is the __init__ doing? i mean, you can just delet it and the code works the same... so what is it actualy duing?

[@ReuvenLerner]

__init__ sets attributes on the new instance. If you aren't setting any attributes, then __init__ isn't necessary, and can indeed be removed without consequence. But if you are setting attributes in __init__, then you can't just get rid of it!

[@isimbulmakcokolay]

great content, thanks!

[@JesseUnderdog]

Dude, you're good at teaching :P

[@ReuvenLerner]

Thanks so much for the kind words!

[@cetilly]

There is also the __init__.py file, which would be another good topic

[@ReuvenLerner]

Yes, a good topic to discuss, for sure! Unfortunately, there's no connection between the __init__ method and the __init__.py file, except that both are dealt with at the start of something.

[@tarykhai9175]

So much great info, definitely deserved more views!!!

[@fusebox9725]

If the dunder method is used to initialize attributes then what's the use of walrus operator? Btw great video I'm still learning.

[@ReuvenLerner]

Glad you enjoyed! The walrus operator is for assignment, just like =, but it is an expression, meaning that it also returns a value. Dunder-init is about assigning values to a new object just after it was created; you could use either = or := to assign those attributes, but the point is convenience, that it happens automatically.

[@chriskeo198]

can i get a signed copy of that book!

[@ReuvenLerner]

Um.... I've signed a handful at Python conferences, but other than that, or you coming to Israel, I don't really have an easy way to do that, other than sending a copy in the mail.

[@dropcloud7114]

Is this w3 school

[@ReuvenLerner]

Nope -- I'm an independent Python trainer, in business since 1995. Welcome to my channel!

[@dropcloud7114]

@@ReuvenLerner ok thanks. You teach all python stuff here

[@hangout7081]

@@dropcloud7114 yeah.