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Can a pointer to base point to an array of derived objects?
...he next Rectangle, but a pointer to what would be the next Shape in a presumed array of Shape. Of course, this is undefined behaviour. In your case, you're being lucky and getting a crash.
Using a pointer to Rectangle makes the indexing work correctly.
int main()
{
Rectangle * shapes = new Rect...
Pacman: how do the eyes find their way back to the monster hole?
...nd a lot of references to the AI of the ghosts in Pacman, but none of them mentioned how the eyes find their way back to the central ghost hole after a ghost is eaten by Pacman.
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Express: How to pass app-instance to routes from a different file?
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Use req.app, req.app.get('somekey')
The application variable created by calling express() is set on the request and response objects.
See: https://github.com/visionmedia/express/blob/76147c78a15904d4e4e469095a29d1bec9775ab6/lib/express.js#L34-L35
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Convert SVG to PNG in Python
... is an Ubuntu python-rsvg package providing it. Searching Google for its name is poor because its source code seems to be contained inside the "gnome-python-desktop" Gnome project GIT repository.
I made a minimalist "hello world" that renders SVG to a cairo
surface and writes it to disk:
import ca...
Different dependencies for different build profiles
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To quote the Maven documentation on this:
A profile element contains both an optional activation (a profile trigger) and the set of changes to be made to the POM if that profile has been activated. For example, a project built for a test environme...
Unicode (UTF-8) reading and writing to files in Python
I'm having some brain failure in understanding reading and writing text to a file (Python 2.4).
14 Answers
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How to implement a binary tree?
Which is the best data structure that can be used to implement a binary tree in Python?
18 Answers
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In Python, how do I read the exif data for an image?
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You can use the _getexif() protected method of a PIL Image.
import PIL.Image
img = PIL.Image.open('img.jpg')
exif_data = img._getexif()
This should give you a dictionary indexed by EXIF numeric tags. If you want the dictionary indexed by the actual EXIF tag na...
Message Queue vs Message Bus — what are the differences?
And are there any? To me, MB knows both subscribers and publishers and acts as a mediator, notifying subscribers on new messages (effectively a "push" model). MQ, on the other hand, is more of a "pull" model, where consumers pull messages off a queue.
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Why can't a 'continue' statement be inside a 'finally' block?
... no exception is thrown, finally will run when other control transfer statements inside the try/catch block run, like a return, for example, which brings the same problem.
In short, with the semantics of finally it doesn't make sense to allow transferring control from inside a finally block to the ...