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How do you create different variable names while in a loop? [duplicate]

...can do this is with exec(). For example: for k in range(5): exec(f'cat_{k} = k*2') >>> print(cat_0) 0 >>> print(cat_1) 2 >>> print(cat_2) 4 >>> print(cat_3) 6 >>> print(cat_4) 8 Here I am taking advantage of the handy f string formatting in Pytho...
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Functional programming - is immutability expensive? [closed]

...’d like to clarify some points. The “in-place” quicksort isn’t really in-place (and quicksort is not by definition in-place). It requires additional storage in the form of stack space for the recursive step, which is in the order of O(log n) in the best case, but O(n) in the worst case. Im...
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How to overcome TypeError: unhashable type: 'list'

...used to compare dictionary keys during a dictionary lookup quickly. Internally, hash() method calls __hash__() method of an object which are set by default for any object. Converting a nested list to a set >>> a = [1,2,3,4,[5,6,7],8,9] >>> set(a) Traceback (most recent call last...
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What are 'closures' in .NET?

...thod and the variable j [CompilerGenerated] private sealed class <>c__DisplayClass2 { public <>c__DisplayClass2(); public void <fillFunc>b__0() { Console.Write("{0} ", this.j); } public int j; } for the function: static void fillFunc(int count) { ...
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C# pattern to prevent an event handler hooked twice [duplicate]

...ution and the best one (considering performance) is: private EventHandler _foo; public event EventHandler Foo { add { _foo -= value; _foo += value; } remove { _foo -= value; } } No Linq using required. No need to check for null before cancelling a subscrip...
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Permanently add a directory to PYTHONPATH?

...n environment variable in your chosen platform and shell, since it's not really a programming question per se. share | improve this answer | follow | ...
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Why doesn't GCC optimize a*a*a*a*a*a to (a*a*a)*(a*a*a)?

...scientific application. One thing I noticed is that GCC will optimize the call pow(a,2) by compiling it into a*a , but the call pow(a,6) is not optimized and will actually call the library function pow , which greatly slows down the performance. (In contrast, Intel C++ Compiler , executable ...
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How to download an entire directory and subdirectories using wget?

...nd I am only able to access the files through a browser. The base URLs for all the files is the same like 8 Answers ...
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How do I load a file from resource folder?

...e examples of how that class is used: src\main\java\com\company\test\YourCallingClass.java src\main\java\com\opensymphony\xwork2\util\ClassLoaderUtil.java src\main\resources\test.csv // java.net.URL URL url = ClassLoaderUtil.getResource("test.csv", YourCallingClass.class); Path path = Paths.get(ur...
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When should you use constexpr capability in C++11?

... "function that always returns 5" is breaking or diluting the meaning of "calling a function". There must be a reason, or a need for this capability or it wouldn't be in C++11. Why is it there? ...