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Understanding the difference between __getattr__ and __getattribute__
...oesn't explicitly manage and do that via __getattr__ method.
Python will call this method whenever you request an attribute that hasn't already been defined, so you can define what to do with it.
A classic use case:
class A(dict):
def __getattr__(self, name):
return self[name]
a = A()...
Calling parent class __init__ with multiple inheritance, what's the right way?
...ing super() leads to greater flexibility for subclasses.
In the direct call approach, C.__init__ can call both A.__init__ and B.__init__.
When using super(), the classes need to be designed for cooperative multiple inheritance where C calls super, which invokes A's code which will also call supe...
Difference between a theta join, equijoin and natural join
...
A theta join allows for arbitrary comparison relationships (such as ≥).
An equijoin is a theta join using the equality operator.
A natural join is an equijoin on attributes that have the same name in each relationship.
Additionally,...
What is the difference between public, protected, package-private and private in Java?
...e MyClass and I'm doing AnotherClass extends MyClass I will have access to all protected and public methods and properties from within AnotherClass. If I do MyClass myClass = new MyClass(); in AnotherClass somewhere - let's say the constructor - I will only have access to the public methods if it is...
How to save all the variables in the current python session?
I want to save all the variables in my current python environment. It seems one option is to use the 'pickle' module. However, I don't want to do this for 2 reasons:
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What is the __del__ method, How to call it?
...is used, probably not like that: obj1.del() . So, my questions is how to call the __del__ method?
5 Answers
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How can I recover the return value of a function passed to multiprocessing.Process?
... need to know which process is returning which value. If that what you actually need to know about the process, or do you need to correlate between your list of inputs and the list of outputs? In that case, I would recommend using multiprocessing.Pool.map to process your list of work items.
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MySQL vs MongoDB 1000 reads
...very excited about MongoDb and have been testing it lately. I had a table called posts in MySQL with about 20 million records indexed only on a field called 'id'.
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How to combine two or more querysets in a Django view?
...sets into a list is the simplest approach. If the database will be hit for all querysets anyway (e.g. because the result needs to be sorted), this won't add further cost.
from itertools import chain
result_list = list(chain(page_list, article_list, post_list))
Using itertools.chain is faster than...
Get all related Django model objects
How can I get a list of all the model objects that have a ForeignKey pointing to an object? (Something like the delete confirmation page in the Django admin before DELETE CASCADE).
...