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Difference between len() and .__len__()?
Is there any difference between calling len([1,2,3]) or [1,2,3].__len__() ?
4 Answers
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What is the purpose of python's inner classes?
...dden from the outside world.
More readable, maintainable code: Nesting small classes within top-level classes places the code closer to where it is used.
The main advantage is organization. Anything that can be accomplished with inner classes can be accomplished without them.
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Get class name of django model
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Django models are derived from the ModelBase, which is the Metaclass for all models.
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Is there a benefit to defining a class inside another class in Python?
What I'm talking about here are nested classes. Essentially, I have two classes that I'm modeling. A DownloadManager class and a DownloadThread class. The obvious OOP concept here is composition. However, composition doesn't necessarily mean nesting, right?
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Super-simple example of C# observer/observable with delegates
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The observer pattern is usually implemented with events.
Here's an example:
using System;
class Observable
{
public event EventHandler SomethingHappened;
public void DoSomething() =>
SomethingHappened?.Invoke(this, EventArgs.Empt...
Reading a huge .csv file
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You are reading all rows into a list, then processing that list. Don't do that.
Process your rows as you produce them. If you need to filter the data first, use a generator function:
import csv
def getstuff(filename, criterion):
with ...
Get the client IP address using PHP [duplicate]
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I usually don't like nested ternaries, but I really like it in this case...
– Charles Harmon
Jul 18 '14 at 20:49
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Is it intended by the C++ standards committee that in C++11 unordered_map destroys what it inserts?
... always move from its argument. It's supposed to move if the argument is really an rvalue, and copy if it's an lvalue.
The behaviour, you observe, which always moves, is a bug in libstdc++, which is now fixed according to a comment on the question. For those curious, I took a look at the g++-4.8 he...
Using HTML5/Canvas/JavaScript to take in-browser screenshots
Google's "Report a Bug" or "Feedback Tool" lets you select an area of your browser window to create a screenshot that is submitted with your feedback about a bug.
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Getting “cannot find Symbol” in Java project in Intellij
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Select Build->Rebuild Project will solve it
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