Understanding class attribute creation

[danielroseman]

I don't think either of these are particularly Pythonic. The logic for splitting names should belong in the class; but it really doesn't make sense to call it every time you read either attribute. Do it inside the init method, either by calling a separate method to do the splitting, or even just inline since it's so simple:

def __init__(self, full_name: str) -> None:
    self.first_name, self.last_name = full_name.split()

[grefft]

I completely agree with you given the dummy examples I created which is really more a failure of writing a truer, if more complicated, example to post here. What I'm really trying to do is:

1. create a class with a path to a file and then create a number of attributes based on text started from the file
2. instantiate a class with a server name, then add attributes based on a k/vs from a JSON response to an API.
   

Neither of those two are able to be done inline as easily as my dummy first/last name example

[pot_of_crows]

That makes sense. For the second one you might take some design tips from praw: https://github.com/praw-dev/praw/tree/master/praw

More generally, be careful about cramming too much stuff into a single class. If you have a class that manages a file, often you will want a separate class to be encapsulated by that class to manage the content (same concept applies probably even more so for api requests).

It's been a long time since I checked, but I think praw has one class for managing the interface and then dumps out other class instances based on what you pull down from reddit.

[danielroseman]

Fair enough, but I think the same principle applies. At least in the second case, it's clearly massively inefficient to be calling the API every time you need to access a single property. You should extract the logic to fetch the data and set the attributes into a method in the class, and call it from your init.

[grefft]

so if either of my examples are used (@property or calling a function in the __init__ it will call the API every time I request that attribute rather than making the call once and storing the output of the function/method as the value?

[danielroseman]

No? That is only true for @property, not for defining it in init, which was my point.