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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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When to use enumerateObjectsUsingBlock vs. for
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Ultimately, use whichever pattern you want to use and comes more naturally in the context.
While for(... in ...) is quite convenient and syntactically brief, enumerateObjectsUsingBlock: has a number of features that may or may not prove interesting:
enumerateObjectsUsingBlock: will be as fas...
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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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 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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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...
Specify sudo password for Ansible
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For example, you might have a playbook something like this:
- hosts: all
vars_files:
- secret
tasks:
- name: Do something as sudo
service: name=nginx state=restarted
sudo: yes
Here we are including a file called secret which will contain our sudo password.
We will...
What does the caret operator (^) in Python do?
...his way:
1000 # 8 (binary)
0011 # 3 (binary)
---- # APPLY XOR ('vertically')
1011 # result = 11 (binary)
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Is errno thread-safe?
...t errno; so my question is, is it safe to check errno value after some calls or use perror() in multi-threaded code. Is this a thread safe variable? If not, then whats the alternative ?
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