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What is the difference between a static and a non-static initialization code block

...own, just like simple variable initializers) when the class is loaded (actually, when it's resolved, but that's a technicality). Instance initializers are executed in the order defined when the class is instantiated, immediately before the constructor code is executed, immediately after the invocat...
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What does “hashable” mean in Python?

...y and a set member, because these data structures use the hash value internally. All of Python’s immutable built-in objects are hashable, while no mutable containers (such as lists or dictionaries) are. Objects which are instances of user-defined classes are hashable by default; they all comp...
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How do I perform the SQL Join equivalent in MongoDB?

...rect. The new $lookup operator added to the aggregation pipeline is essentially identical to a left outer join: https://docs.mongodb.org/master/reference/operator/aggregation/lookup/#pipe._S_lookup From the docs: { $lookup: { from: <collection to join>, localField: &lt...
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node.js require all files in a folder?

How do I require all files in a folder in node.js? 14 Answers 14 ...
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Why does ReSharper tell me “implicitly captured closure”?

... use. The compiler generates a class for both lambda expressions and puts all variables in that class which are used in the lambda expressions. So in my example g and i are held in the same class for execution of my delegates. If g is a heavy object with a lot of resources left behind, the garbage...
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Remove all occurrences of a value from a list?

...on over the filter+lambda; the former is more readable in addition to generally more efficient. – habnabit Jul 21 '09 at 4:28 17 ...
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BaseException.message deprecated in Python 2.6

...of the exception hierarchy. Provides an 'args' attribute that contains all arguments passed to the constructor. Suggested practice, though, is that only a single string argument be passed to the constructor.""" __str__ and __repr__ are already implemented in a meaningful way, especiall...
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How do I run all Python unit tests in a directory?

...it test module is of the form test_*.py . I am attempting to make a file called all_test.py that will, you guessed it, run all files in the aforementioned test form and return the result. I have tried two methods so far; both have failed. I will show the two methods, and I hope someone out there ...
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How to implement a binary tree?

...ice implementation. I'm just here to point out some style stuff. python usually does node is not None instead of your (node!=None). Also, you can use the __str__ function instead of the printTree method. – Jeff Mandell Oct 18 '15 at 2:30 ...
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Why can't I overload constructors in PHP?

I have abandoned all hope of ever being able to overload my constructors in PHP, so what I'd really like to know is why . ...