104 questions
4
votes
3
answers
199
views
What happens if __del__ is defined as an async def coroutine in Python (CPython 3.12)?
I'm experimenting with asynchronous patterns in Python and was curious what happens if I define a __del__ method using async def in Python 3.12.
For example:
class MyClass:
async def __del__(self):...
- 1
3
votes
3
answers
728
views
Using lru_cache on a class that has a classmethod
I want to cache instances of a class because the constructor is complicated and repeated uses won't alter the contents. This works great. However, I want to create a classmethod to clear the cache. In ...
- 12k
2
votes
1
answer
587
views
best way to create serializable data model
somewhat inexperienced in python. I am coming from C# world, and I am trying to figure out what is the best practice to create a data structure in python that:
can have empty fields (None)
can have ...
- 469
-1
votes
1
answer
251
views
python: create empty dataclass and populate it on demand
python newbie: I need to create an empty data model class, populate it with values and then convert it to JSON string, however i am missing something important here. see error below
my data class:
...
- 191
0
votes
2
answers
113
views
Python: Magic method for when the object's reference count changes?
I want to a method that runs when object reference count is changed. is there a method like the following code ?
class Foo():
def __method__(self):
print("ojbect reference count is ...
- 119
0
votes
0
answers
122
views
Why cls() in a classmethod does not provide argument hints the way that directly calling the class constructor does?
I'm trying to make a subclass with a @classmethod that would take as arguments an instance of its superclass and kwargs for its other fields. The goal is to be able to take an object of the general ...
0
votes
0
answers
106
views
Should I use Model objects from library or make it myself?
I'm working with gitlab webhooks and I need to choose which data model to use in my project.
I'm using the Python-gitlab library to work with gitlab, and this library has its own data models for all ...
6
votes
2
answers
615
views
Python dunder methods wrapped as property
I stumbled upon this code that I found weird as it seems to violate the fact that python builtins call dunder methods directly from the class of the object. Using __call__ as an example, if we define ...
- 99
0
votes
3
answers
106
views
How to represent the numbers 0 to 3, taking up 2 bits of memory in python
I'm writing code for a Deep Q Network in python. My computer has 32GB of memory but I run into significant issues as the training goes on because the replay buffer maxes out the RAM.
I'm looking ...
- 29
1
vote
1
answer
61
views
classmethods and data model methods, implementing operands over classes or types
Here is what you would expect if you try and use the add operand over a type and int or between two type objects.
>>> class Foo:
... pass
...
>>> class Bar:
... pass
...
>&...
- 850
0
votes
1
answer
491
views
Are there any unique features provided only by metaclasses in Python?
I have read answers for this question: What are metaclasses in Python? and this question: In Python, when should I use a meta class? and skimmed through documentation: Data model.
It is very possible ...
- 137
3
votes
2
answers
2k
views
Wrapping derived class method from base class
Imagine I have a base and a derived class like so:
class A:
def foo(self):
pass
class B(A):
def foo(self):
pass
I wish to wrap calls foo calls made by instances of B. ...
- 3,908
2
votes
1
answer
520
views
How can I access the weakref object of the class itself through the class?
As far as I know, __weakref__ is a descriptor defined in class, so that if it invoked from the instances of the class, it will give the weakref object:
from weakref import ref
class A:
pass
obj =...
- 17.1k
11
votes
1
answer
3k
views
Where is the default behavior for object equality (`==`) defined?
According to the object.__eq__() documentation, the default (that is, in the object class) implementation for == is as follows:
True if x is y else NotImplemented
Still following the documentation ...
- 19.2k
0
votes
1
answer
561
views
Usage of __setattr__ to rewrite whole method of library class issue: missing 1 required positional argument: 'self'
I've got some imported packages with tricky structure
and need to call some method that bases on lots of other methods
with non-default parameters, which are not class attributes themself like ...
- 172