I have been programming regularly in Python for a few years and I keep watching this Video. Again and again I get something new from it.

Reymond Hettinger and James Powell: I owe a great deal to these two men.

One of the best performances on PyCon USA I've seen. Thanks a lot for upload!

"Who learned something new?" *I* did.

Raymond Hettinger style of delivery is fantastic and the content is very good delivered in a succinct manner.

Thank you for excellent explanation of what certain functions are meant for in Python and not just explaining how they work! Just cleared out a lot of very important topics! Just great!

Brilliant delivery. Whether you are interesting in programming or not, it's worth watching, if just for the overall business process implications.

This was so entertaining that I'll swap out my movie tonight for this video. Thanks!

That's part of his "signature", I actually took almost 80 hours of training from Raymond Hettinger and that's one of the teaching techniques he continuously uses throughout his classes to reinforce ideas and concepts, and let me tell you it is very effective, definitely one of the best courses I've ever taken.

This guy is a great teacher ... at least 8 minutes into the video. I like what he has to say ... and always good when you hear what lots of people think that is wrong too.

Wow this was an amazing lecture! Great for someone who knows some python, and wants to learn all about classes in Python. Apart from the summary slide at 45:00, some of the main things I learnt were: 1) See how people use your code (through fast feedback loops), and make sure new changes don't break their code. Think especially about people who will make subclasses from your classes. Expect that there is a good way to meet new requirements while not breaking old user code 2) Add just what you need as part of the Agile process. It seems that Python is great for Agile development because you can get up and running with very simple code, and add more functionality in the future without changing the API. 3) Python is different from Java or C++. I guess each language has their own style, and it is a good idea to learn to do things the right way in any language you learn, rather than bring the old habits along.

Such a talented speaker, really interesting presentation to watch

Every programming class should be taught this way. I love how this is implemented in a project-style manner. I wish I learned OOP this way.

This, is, incredibly thorough. Thanks so much.

Great video. Thanks Raymond.

Having seen this video up to 20', I could easily replace Raymond's lectures over my netflix subscription

I think it's good. :) It gives Raymond feedback so he can adapt the talk to the technical level of the audience.

God damn it, I almost spit out my coffee when he said, "Reproducible results? Oh, that's a new feature in science. How often do you get that?" 16:04

Awesome! Than you, Raymond.

Wow, this was really amazing, I definitely learned something new today.

Great talk. Everyone I share this with gets a kick and yes, they learn something new.

This was a fantastic talk...

I am a python novice and not got a hold on class (OOP) most of whatever you said in pure technical sense went right over my head but the delivery and style, I am fan now and I think now I will be Ninja when I start OOP

thanks Ray i love it it's awesome brother bigup

amazing. learned something new!

This is a must-see video for Pythonistas.

I learned something new! Now I have to go change all the getters and setters I thought I needed because I wanted to do more than just store the property.

i dont even use python regularly and i watched this all the way through

Here are the contents of the slides with comments in the form of an IPython Notebook. nbviewer.ipython.org/urls/dl.dropboxusercontent.com/u/5095342/IPython%20Notebooks/Python%27s%20Class%20Development%20Toolkit.ipynb

Flippin Big RH absolutely doing WORK back in the day. Guy’s a beast am I right?’

this was amazing. can't believe i hadn't come across this before. and i feel like an idiot for not having done so.

Great video/content thanks for recording it in 480p! 2013

I learned something new

That moment when Raymond goes "..the opposite of privacy - [...] freedom" 37:42

Would area() be better as an @property, as well? Seems like that would be a more python-like implementation and would make the calling code easier.

Must see for every Python programmer))

I like how this makes me able to use Python just like Ruby

17:30 so classic python. Now we have ppl demanding type ints. I do not feel icky not knowing what types are being passed.

Raymond: if you wish hard enough, the fairy godmother appears .. I guess we all wished hard enough and so Raymond appeared

"Properties are something you can do in a dynamic language but not in compiled ones"... Unless you use turbopascal

Code is read more than is written. So next time you are reading a piece of code and see obj.radius = 3 Do you know if you are setting a variable or calling a function?

Is there any book with this kind of explanation? These videos are best tutorial.

I learned several new things, but it's the "proleptic gregorian calendar", not "apoplectic" or whatever he was trying to say :)

Kind of weird how much this guy looks like Ray Liotta.

“TRUE OR FALSE: is this my first Rodeo?”

I thought I knew how to make a class in python. This video showed me that I know nothing.

The first two things I did understand. After that I didn't understand anything. Is there a way to learn what subclasses are and when to use, what instanciate really means and when to use these class methods and static methods?

I learned sth new

If __init__ isn't a constructor. What's the actual constructor of python, is it __new__?

Summary: Toolset for New-Style Classes 1. Inherit from *object()* 2. *Instance Variables* for information unique to an instance. 3. *Class Variables* for data shared among all instances. 4. *Regular Methods* need "self" to operate on instance data. 5. *Class Methods* implement alternate constructors. They need "cls" so they can create subclass instances as well. 6. *Static Methods* attach functions to classes. They don't need either "self" or "cls". Static methods improve discoverabiity and require context to be specified. 7. *@property* lets getter and setter methods be invoked automatically by attribute access. This allows Python classes to freely expose their instance variables. 8. *__slots__* variable implements the Flyweight Design Pattern by suppressing instance dictionaries. 9. *__DoubleUnders__* for class level references.

36:25 - 37:53 .__ == freedom

7:06 10:26 coding a reusable vs constant

I really can't see the problem with self.perimeter() methode inside area()... this is what I would have done in another programming language like Java because "this" will always use the method of the class of the object if it exist

What does he say at 11:13? "and upload it to ???"

A great reddit thread discussion on the same : www.reddit.com/r/Python/comments/2zp0jy/probably_the_best_lecture_ive_seen_raymond/?st=jbsytpb3&sh=deb8db8c

#KeyTakeAways 7:15 If you don't have variables don't belong to that instance use class variables. Not instance variables. 7:55 __init__ is not constructor. It is initializer. 9:00 Python classes are not similar to the C++ or Java classes. They are more like namespaces or dictionaries. 11:48 YANGNI 18:47 Exposing variables and changing them outside of the class is common and normal in Python world. 21:30 When you create an object and call a attribute or method ( including __init__ ) Python first looks called class itself. Then looks parent classes recursively. 21:56 Extending and overriding. 26:26 Alternative constructors with @classmethod decorator 32:00 @staticmethod decorator 33:50 Creating a private variable and assign the method to that private variable. It is a good way of protecting your subclasses. 35:35 Better way of protecting your subclasses assigning the method to a dundervariable. 39:26 Accessors and mutators. When you set circle.radius = 5, @radius.setter decorated function runs ----> www.python-course.eu/python3_properties.php 41:44 __slots__ and lastly, how to do an engaging presentation.

George Clooney of Python!

39:31 - shouldn't __init__ do *self.diameter* = radius * 2.0 ? Otherwise, you're violating your own ISO-222220

Camera guy fall asleep at the end or something? Show me the fucking slides, damnit!

ok I'm confused (i'm very new to python), I understand that you should use reusable components, but what's the point of using Math.pi? It wont ever change (can I modify it on a large scale inside Python?) and if I ever need to have higher or lower precisions I'd have to rewrite the application all the same, wouldn't it make more sense to just have a Pi object where we could both have the hability fiddle with its precision without adding overhead?

I think the final few examples (39:45ish) using @property and @setter are incorrect because the self.radius should be self._radius, otherwise the init will try to call the setter for radius, and since no diameter is bound, it will error.

can't do on a compiled language? swift does it. probably a bit better too.

When switching from radius to diameter, doesn't he need to change his __init__ method to `self.diameter = radius * 2.0`? (Especially after settings __slots__ = ['diameter'].)

Great talk! I wrote down the code in the talk here www.lvguowei.me/post/python-class-toolkit/ for easy reference.

He's like a way smarter Norm Macdonald

hah, "consenting adult's language"

who needs more then 6 decimal_digits of pi?

"Is python about privacy? No is a consenting adult language" says after explaining how to workaround the fact that python does not have private and protected methods and hack a private method "There must be a better way" Yea, real private and protected methods.

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I still find it amusing that Python programmers actually think they write real code. They actually think python is object orientated or functional. Python is none of those things, it's a script language. It's for solving problems too simple to bother a real language and project with. __init__ cannot initialise instance variables because python doesn't really have instance variables. It has a "self" thing with a dictionary in it. Initialise just adds a dict entry. You could of course just have set it yourself in the members dict. It's not a class, it's a dictionary and a bunch of function pointers. It can't be OOP as I don't think it correctly implements any of the corner stones of OOP, so just can't be classed as an OOP language. I mean PHP's OOP implementation was probably more complete than Pythons. It's only OOP to stop OOP programmers whining. It suffers the same as all "next generation" language suffer. It starts out with a clear, clean, simple ethos. It's successful and get adopted enough to survive. Then immediately all the people who adopted it start trying to use it to do everything... because oddly a lot of programmers strive to be single tool, single trick ponies and so they try and adapt their language of choice well outside of it's original ethos, add a bunch of junk which basically breaks the ethos and it becomes a bloated mess. I'll give you 3 reasons nobody uses Python for anything serious. Dynamic typing - untestable. Interrupter language - untestable. Once your application gets to a certain size, python becomes unmaintainable. Once your data/processing gets to a certain size python becomes non-performant. It's fine for it's intended purpose as a "quick", "convenient", "intuitive" utility language. Maybe a new Perl. Watching python programmers bigging themselves and their language up on the grand scheme of software engineering is actually quite cute. Awww.

I learned nothing new from this.

Wrong...you CAN make the instance variables private by prefixing them with two underscores: *self.__radius*.

_init_. haha. python is a good joke.

Excellent, but stop saying "who learned something new" its tedious

Only theory demonstration. It's a very boring class.