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How do I import the Django DoesNotExist exception?

...y of the model itself, in this case Answer. Your problem is that you are calling the get method - which raises the exception - before it is passed to assertRaises. You need to separate the arguments from the callable, as described in the unittest documentation: self.assertRaises(Answer.DoesNotExis...
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What's the difference between a Python “property” and “attribute”?

I am generally confused about the difference between a "property" and an "attribute", and can't find a great resource to concisely detail the differences. ...
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Structure padding and packing

.... A note though - unaligned memory access is slower on architectures that allow it (like x86 and amd64), and is explicitly prohibited on strict alignment architectures like SPARC. share | improve t...
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What do *args and **kwargs mean? [duplicate]

...r **kwargs as the last items in your function definition’s argument list allows that function to accept an arbitrary number of arguments and/or keyword arguments. For example, if you wanted to write a function that returned the sum of all its arguments, no matter how many you supply, you could wr...
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Calling Objective-C method from C++ member function?

I have a class ( EAGLView ) which calls a member function of a C++ class without problems. Now, the problem is that I need to call in that C++ class a objective-C function [context renderbufferStorage:GL_RENDERBUFFER fromDrawable:(CAEAGLLayer*)self.layer]; which I cannot do in C++ syntax...
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What does 'super' do in Python?

... What's the difference? SomeBaseClass.__init__(self) means to call SomeBaseClass's __init__. while super(Child, self).__init__() means to call a bound __init__ from the parent class that follows Child in the instance's Method Resolution Order (MRO). If the instance is a subclass of ...
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Is there a range class in C++11 for use with range based for loops?

...:irange, which is a bit more focused in scope. C++20's range library will allow you to do this via view::iota(start, end). share | improve this answer | follow ...
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How to make a valid Windows filename from an arbitrary string?

...: Bar" that I want to use as a filename, but on Windows the ":" char isn't allowed in a filename. 14 Answers ...
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How to read keyboard-input?

... mixing different Pythons here (Python 2.x vs. Python 3.x)... This is basically correct: nb = input('Choose a number: ') The problem is that it is only supported in Python 3. As @sharpner answered, for older versions of Python (2.x), you have to use the function raw_input: nb = raw_input('Choose...
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How to find out what type of a Mat object is with Mat::type() in OpenCV

..."; r += (chans+'0'); return r; } If M is a var of type Mat you can call it like so: string ty = type2str( M.type() ); printf("Matrix: %s %dx%d \n", ty.c_str(), M.cols, M.rows ); Will output data such as: Matrix: 8UC3 640x480 Matrix: 64FC1 3x2 Its worth noting that there are also Matr...