Python Dataclasses: Here's 7 Ways It Will Improve Your Code

Dataclasses in Python simplify the creation of data structures with minimal code, and gives you a lot of useful utility right out of the box.

📚 Chapters
00:00 Introduction
00:25 What is a Dataclass?
01:06 Create Data Structures with Less Code
02:34 Descriptive REPR
03:30 Built-in Equality Check
04:11 Fields and Default Values
06:19 Frozen Objects
07:16 Ordered Objects
08:21 Convert To and From Dict

#pixegami #python

[pixegami]

Here's some additional important details about @datacalsses that a viewer called out (thank you @FrederikSchumacher):
1. Type annotations are not validated or enforced — they can act as a nice guide for you, but be aware that Python won't throw and error or warn you if you use a different type in runtime.
2. Frozen (constant) lists can have items appended/removed (similar to a constant array in Typescript). If you want the list operations itself to be immutable too, try using tuples instead.
3. **kwargs initialisation works on the initial instance of the dataclass, but not on nested dataclasses or fields (there you might want to look at Pydantic instead, which I believe does do that).

[Aceptron]

Dude your level of detail and pace is just PERFECT! I have easily seen hundreds if not thousands of videos on YouTube regarding CS. You're one of the best on that aspect! And I love how you leave further details for documentation, which is necessary anyways!

[kpro]

Man, I love it when I find a youtuber who is clear and thorough. You rock!!

[FrederikSchumacher]

Really solid video. I'm really glad the options frozen and order where presented. I wish you had mentioned something potentially confusing about the type annotations: although the type annotations are required for the fields declaration, they're not validated or enforced. Meaning it's possible to declare a field "name: str" but then assign some other type of value. Another gotcha is even when using frozen, this only applies to assignment to the fields, not the values. So something like "tags: list = field(default_factory=list)" still allows modification of the list (eg. using append or extend).
And one more gotcha about the **kwargs initialization: this only applies to the initial instance, not any nested fields using dataclasses - that's related to the aforementioned field types not being "used" internally. This can become potentially confusing and lead to bugs, if one isn't aware of that. So, while dataclasses.asdict works recursive, there's not really an equivalent fromdict and using **kwargs can introduce bugs.

[byitkc]

Great introduction to dataclasses! I especially appreciated the tip about making dataclasses immutable, something I will definitely use on my future projects. Thank you!

[obc]

Nice introduction to dataclasses, Thanks

[rboigjc]

The dataclass decorator provides useful features, but it is often used even when it doesn't fit the name dataclass, which can decrease code readability. In fact, it is confusing to see the dataclass decorator attached to classes that are only used once. The simplification of __init__ and __repr__ should be separated and implemented under different names.

[ubiquitousonegroup]

I have a question I would like to email it to you, I don't want to look bad in the comment section😗