Abstract Base Classes are non-instantiable classes used to define the expected behaviour of subclasses.
Questions tagged [abc]
280 questions
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0 answers
Check if instance is of object extending an ABC
The structure I have looks like this:
Parent(abc.ABCMeta) -> Foo(Parent)
Parent(abc.ABCMeta) -> SubParent(abc.ABCMeta, Parent) -> Bar(SubParent)
Then, say we have instances like so,
x = Foo()
t = Bar()
From this design, is it possible to answer…
Debosmit Ray
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2 answers
python abc subclasshook has no effect when class is derived
There is no way to return False from issubclass when class is derived from class with __subclashook__ implementation. I modified code from:
python subclasscheck & subclasshook
I only added '(Sized)' to both class definitions:
from abc import…
PiotrB
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1 answer
Abstract Property on __name__ not enforced
Consider the following sample code:
from abc import ABC, abstractmethod, abstractproperty
class Base(ABC):
@abstractmethod
def foo(self) -> str:
print("abstract")
@property
@abstractmethod
def __name__(self) -> str:
…
Keozon
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0 answers
python: isinstance(value, Sequence[Real])
Python's typing module allows containers of specific object types to be described, such as Sequence[numbers.Real]. However, the container interfaces in collections.abc do not accept such parameters, so I can only check isinstance(value,…
blue_note
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1 answer
Updating Classes that inherit from abstract classes
I have an abstract class ship.
from abc import ABC, abstractmethod
class ship(ABC):
def __init__(self):
...
@abstractmethod
def do_stuff(self,stuff,things):
pass
I have multiple classes that inherit from it…
David
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- 9
0
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1 answer
running ABC inside YOSYS returns ' Warning: Detected 1 multi-output gates'
When using YOSYS I call abc command:
abc -liberty mycells3.lib
mycells3.lib is a simple custom technology library based on the example library provided in YOSYS distribution where I added ADDER cell (named FAX1):
library(demo) {
cell(BUF)…
Omer Shlomovits
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- 2
0
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1 answer
Define private variable of class as abstract
I want to know what is the correct way to make my class's private variables as abstract. Let me summarize the properties of my variable:
Class variable
private
abstract
Structure of my classes is like:
from abc import ABCMeta
class…
Moinuddin Quadri
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1 answer
Child classes implement a MooseX::Interface with MooseX::ABC (Abstract Base Class)
I am trying to force all child classes of an Abstract Base Class to implement an interface. When I try add with '' to the ABC, it requires me to implement the required methods immediately and add sub {} for each interface…
yougotborked
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- 1
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1 answer
Python 2.7 -- Calling an Abstract Base Class' method from an Instance
I am searching for the proper way to call an abstract base class' method from an instance of a class that is registered as a subclass of the ABC. This is some very basic test code to first figure out how to make this work. This is where I am…
user4766915
0
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0 answers
Calling subclass method (overridden abstract class method) from abstract class method in python
I would like to call the overridden abstract class method (subclass method) from the abstract class method, but getting several errors. Could you help me, please?
My concept:
import abc
from my_module import Format, Message
class…
Petr Krampl
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0
votes
1 answer
How to write a Python ABC with a concrete initializer in python 2.6 to 3.5?
The Context
I have a python application with a relatively involved class hierarchy. It needs to work with python 2.6 up to python 3.5 (a big range, I know!), and I've been having particular problems with ABCs.
I'm using the six library's…
sirosen
- 1,716
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0
votes
1 answer
Can I unregister a class as an `Iterator`?
I've been handed code with a class that incorrectly subclasses the abstract base class collections.Iterator. It doesn't follow the Iterator contract and this flawed inheritance relationship causes issues downstream. Is there any way to unregister…
MRocklin
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votes
1 answer
Duck-typable classes, ABC, iheritance, __new__
I'm writing a test system that uses, amongst other things, a data source. When running, it will read a bunch of instruments, but for testing and development of the back end, I want it to read a file, or return random numbers. In the future, I know…
Neil_UK
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0
votes
2 answers
How to use Abstract Base Classes in Python?
Following this tutorial I'm trying to use Abstract Base Classes in Python. So I constructed two files:
basis.py:
import abc
class PluginBase(object):
__metaclass__ = abc.ABCMeta
@abc.abstractmethod
def load(self, input):
…
kramer65
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Distinguish abstract base class from implementation
Developing a metaclass that provides self-registration of subclasses (somewhat similar to this idea), I came across the following problem:
Given a class that may be either an abstract base class or an implementation of one, how do I distinguish…
Emilia Bopp
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