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Usage of __slots__?
What is the purpose of __slots__ in Python — especially with respect to when I would want to use it, and when not?
11 A...
Can someone explain __all__ in Python?
...e and more, and I keep seeing the variable __all__ set in different __init__.py files. Can someone explain what this does?
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Difference between __getattr__ vs __getattribute__
...__getattr__ is only invoked if the attribute wasn't found the usual ways. It's good for implementing a fallback for missing attributes, and is probably the one of two you want.
__getattribute__ is invoked before looking at the actual attributes on the object, and so can be tricky to implement corr...
How to “perfectly” override a dict?
...
You can write an object that behaves like a dict quite easily with ABCs (Abstract Base Classes) from the collections.abc module. It even tells you if you missed a method, so below is the minimal version that shuts the ABC up.
from co...
What are metaclasses in Python?
...es. A class is an instance of a metaclass.
While in Python you can use arbitrary callables for metaclasses (like Jerub shows), the better approach is to make it an actual class itself. type is the usual metaclass in Python. type is itself a class, and it is its own type. You won't be able to recrea...
What is the difference between public, protected, package-private and private in Java?
...rotected and private , while making class and interface and dealing with inheritance?
29 Answers
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In Python, how do I determine if an object is iterable?
Is there a method like isiterable ? The only solution I have found so far is to call
21 Answers
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Overloading Macro on Number of Arguments
...follow
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edited Aug 1 '12 at 16:13
answered Aug 1 '12 at 16:08
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What is the difference between __init__ and __call__?
I want to know the difference between __init__ and __call__ methods.
13 Answers
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What is the most efficient/elegant way to parse a flat table into a tree?
... all popular SQL databases support recursive queries in standard syntax.
WITH RECURSIVE MyTree AS (
SELECT * FROM MyTable WHERE ParentId IS NULL
UNION ALL
SELECT m.* FROM MyTABLE AS m JOIN MyTree AS t ON m.ParentId = t.Id
)
SELECT * FROM MyTree;
I tested recursive queries in MySQL 8.0...