Questions tagged [python-attrs]
Use for questions about the third-party Python library for data classes
python-attrs
160
questions
1
vote
1
answer
758
views
cattrs.structure with nested dictionaries and attrs.define( converter=foo )
I am having issues structuring dicts, which contain invalid data, into @attrs.define decorated classes, but should be handled with attrs.define converters.
I have managed to get it to work with Foo( **...
- 43
0
votes
2
answers
466
views
python attrs inherited field value gets overwritten
I have some attrs classes that inherit from a base class. The parent class has a field that is also an attrs class.
If I instantiate two instances of the child classes and set the common inherited ...
- 460
0
votes
1
answer
392
views
How to customize attrs field hash
I'd like to use a Numpy array as a field value while keeping my attrs class hashable. For that purpose, I found joblib's hash() function to be a good means of hashing Numpy arrays. Is there any ...
- 621
0
votes
1
answer
832
views
How to annotate attrs field with validator?
I am having trouble annotating attrs class attribute.
I am using NewType for defining new UserId type and attrs frozen classes.
This is code where mypy doesn't complain and everything is alright:
from ...
- 83
0
votes
1
answer
734
views
Using cattrs / attrs where attr name does not match keys to create an object
I am looking at moving to cattrs / attrs from a completely manual process of typing out all my classes but need some help understanding how to achieve the following.
This is a single example but the ...
- 1,019
4
votes
1
answer
2k
views
Is there an easy way to construct a pandas DataFrame from an Iterable of dataclass or attrs objects?
One can do that with dataclasses like so:
from dataclasses import dataclass
import pandas as pd
@dataclass
class MyDataClass:
i: int
s: str
df = pd.DataFrame([MyDataClass("a", 1), ...
- 361
0
votes
0
answers
32
views
Different objects are preserving the state using attrs
I'm making some experiments using attrs, but I'm experiencing some unexpected behaviors in the following code:
I created a class as this one:
@define
class User:
name = field()
errors = field(...
- 376
1
vote
1
answer
531
views
Serialising with cattrs and want to omit field x1 string field
Using cattrs to structure data and I want to omit x1 string field.
I want to perform a trivial cleanup on strings that have been passed in except for the password field.
I can get it to work on all ...
- 239
1
vote
0
answers
275
views
Add caching to __new__
I have a frozen class (decorated with attrs.frozen). However, the program might have to create many instances of that class. Since they are immutable and I only want to read from them, I want some ...
- 99
1
vote
1
answer
159
views
What happens exactly when a python class instance use dot to access attributes?
Suppose a class A is defined as:
class A:
def __init__(self, val):
self.val = val
After A is instantiated by a = A(3), what methods will be called by executing a.val? In other words, what ...
- 21
4
votes
2
answers
491
views
attrs convert list[str] to list[float]
Given the following scenario:
import attrs
@attrs.define(kw_only=True)
class A:
values: list[float] = attrs.field(converter=float)
A(values=["1.1", "2.2", "3.3"])
...
- 802
0
votes
0
answers
245
views
Type annotation in python-attrs
I'm going to use attrs for a class within my ETL process and currently I struggle with its type annotation capabilities.
For instance, I have this code:
@define(auto_attribs=True, kw_only=True)
class ...
- 913
0
votes
2
answers
544
views
How to override an attrs class instance with another one when the values are not None
My goal is to be able to merge multiple instances of the same attrs class and skip 'None' values.
This allows me to create default values and later override them when I need to.
An example of the ...
- 355
-1
votes
2
answers
54
views
Define custom atrributes in attr module
I'm looking for way, that I can define class attributes as I want.
For example, I tried this way:
@attrs.define
class MyClass:
pass
MyClass(a=1, b=2)
But recieving the TypeError:
TypeError: ...
0
votes
0
answers
321
views
Exclude all attrs auto-generated methods from sphinx
I have a simple attrs data class:
from attrs import frozen
@frozen
class Person
raw: str
I document it with the simplest *.rst file:
.. autoclass:: api.main.person.Person
:members:
:...
- 6,760