Do We Still Need Dataclasses? // PYDANTIC Tutorial

Thanks! Good stuff.

Thanks!

do u have hair implants

One little advantage of pydantic is that mutable default arguments are easier to use. I know dataclasses have the field possibility, but that has its limits and is a little ugly.
Also the validation implementation is a lot nicer in the newer versions :)

i dont understood This but u are able in coding thinks

amazing!

bro u look like Ashish Chanchalani look him up 🙂

can you set an order for the objects in pydantic as for dataclasses?

Thank you so much for this very interesting Pydantic example with both validation levels Arjan! 🙏😀
I'm hoping you'll blend in more Pydantic in your tutorials in the future.
FYI: for the price field you can use Decimal or condecimal with max_digits and decimal_places to more accurately represent money.

Thanks to Yann LeCun's little brother for sharing this knowledge.

Of course, in the real world it's annoying that programs dealing with books insist there has to be an ISBN. I have quite a few books from before the introduction of ISBNs (the oldest is from 1711), and I rejected quite a few cataloguing systems because they wouldn't accept some of my books.

Great tutorial, you earned a new sub.

Will we see Pydantic vs Marshmallow?

ik ruik nederlands

I thought I knew how to define classes and methods 🥲

Excellent tutorial. More of these please, thank you! :-)

hi, into the documentation where explain about how pydantic type more than 2 dates like return example () -> int, str .....

Excellent tutorial on pydantic ! :) Thank you! :) 🙌

As always, excellent video thanks for the time, i learned something now to implement it

When not write a Rest API, why not using attrs instead of pydantic? Is faster and not so resource hungry.

Very interesting stuff. Continue the great work!!

I think if people need to add static type checking to a dynamic language, you are using the wrong language.

You are one of the best if not the best Python Channels that I know of. I am learning a lot from you 😊 Keep up the interesting topics and good work 👍👍👍

Very useful and interesting. Than you Arjan. Small correction to custom exception, there should be inheritance from ValueError. Otherwise FastAPI generates status 500 without Pedantic validation message.

There exist many MANY ideas I would love to code, but I know they are not worth it: no matter in what language I code them.
They are all math ideas. A lot (not all) are coding the solutions to PDEs and ODEs. Some are for papers I wish to publish.
Python is the only language I know, and just barely. Used to know C++, a little Java, and Fortran.

I realize now that the mathematical ideas are simply too complex to be coded.
For example in 2020 I attempted to code computing all infinitely many solutions for a trinomial w=C*z-z^A
where w, C, A are complex numbers. Got close, but there was no way to get roots, z, that are within error limits when plugged back into the trinomial. Had hoped to publish it. But I had to leave it unfinished.
Definitely a HUGE lesson about NOT coding anything deep or complicated:
OTHER than the simplest of calculations, say, with a for loop. In other words, Python is my extension of a handheld calculator.

oh thank you arjan

Decent tutorial. However, the title is misleading: I was expecting an in-depth comparison and pros cons with respect to dataclasses in code.

great video - thanks!

My go to for anything related finishing project. Even as hobby programmer i almost always use your tutorials to make proper code, and in end i remove my bugs from code.

In my opinion (for web service back end programming) Pydantic is the way to go, and then straight into NoSQL, like MongoDB or ElasticSearch. I avoid SQL, Data Classes, and ORM as much as possible. I think SQL is an outdated technology that adds too many problems, complexities, and expenses that do not need to be there. The only case I have for SQL is existing databases, and technologies. When I have a choice, I do not develop any new software using SQL.

Isn't it also possible to validate inputs of dataclasses inside a _post_init_ function? For me no reason to use pydantic.

Thanks a million Arjan for great video. I had a newbie question.
When I changed the order of "@classmethod" and "@pydantic.validator("isbn_10")" the way you suggested(minute 9 video), I did not get the Error. I know the importance of placing decorators in order but I do not understand how come the validation does not take place if I put the "@pydantic.validator("isbn_10")" immediately above the method declaration? it gets overridden?

Bro what is your keyboard? It's so soothng to hear and type i guess?

We need a Guide with Pydantic and ABC or Protocol

Great video Arjan. Subscribed.

@ArjanCodes I'd love to see an updated version using the new Pydantic v2, your thoughts on it, and how it sits now in the pydanticV2 vs dataclasses p3.11 vs attrs

I want to thank you from my bottom of my heart! You have made me a better Data professional!

Pydantic's requirement that the values can only be set from dictionaries is a bit annoying. In some cases reading in an array from JSON is good enough to initialize an object. Not sure why it's so inflexible in this.

this is helpful, thanks for sharing.

Thanks!

how is he able to type that fast?

What is pydantic actually doing in these cases? You can do these checks and raise custom exceptions already without pydantic

any chance you want to update the code for V2?

Dataclasses wouldn't ignore any additional attribute in the dataset used to initialize an instance of the class, it will always raise an Exception, another beautiful thing about pydantic, pydantic will just ignore any extras. Which comes in very handy when using them to model third-party response for syntax highlighting rather then just relying on dictionaries.

I know pydantics better now, thanks. :-)

Another great video. I thought pedantic is just for validation but I know more now. It is great tool to deal with json object like book = [(**list) for list in json]

Moore Eric Gonzalez Jessica Young Ronald