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How do I get SUM function in MySQL to return '0' if no values are found?
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307
Use COALESCE to avoid that outcome.
SELECT COALESCE(SUM(column),0)
FROM table
WHERE ...
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Getting a map() to return a list in Python 3.x
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Do this:
list(map(chr,[66,53,0,94]))
In Python 3+, many processes that iterate over iterables return iterators themselves. In most cases, this ends up saving memory, and should make things go faster.
If all you're going to do is iterate over thi...
Finding all possible combinations of numbers to reach a given sum
...ning, target, partial + [n])
if __name__ == "__main__":
subset_sum([3,9,8,4,5,7,10],15)
#Outputs:
#sum([3, 8, 4])=15
#sum([3, 5, 7])=15
#sum([8, 7])=15
#sum([5, 10])=15
This type of algorithms are very well explained in the following Standford's Abstract Programming lec...
how to set “camera position” for 3d plots using python/matplotlib?
I'm learning how to use mplot3d to produce nice plots of 3d data and I'm pretty happy so far. What I am trying to do at the moment is a little animation of a rotating surface. For that purpose, I need to set a camera position for the 3D projection. I guess this must be possible since a surface can b...
How to convert ‘false’ to 0 and ‘true’ to 1 in Python
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answered Dec 30 '13 at 13:46
Martijn Pieters♦Martijn Pieters
839k212212 gold badges32203220 silver badges28102810 bronze badges
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How to create a video from images with FFmpeg?
...ideo filter instead of -r for the output framerate
ffmpeg -r 1/5 -i img%03d.png -c:v libx264 -vf fps=25 -pix_fmt yuv420p out.mp4
Alternatively the format video filter can be added to the filter chain to replace -pix_fmt yuv420p like "fps=25,format=yuv420p". The advantage of this method is tha...
Scala constructor overload?
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Jon McAuliffeJon McAuliffe
3,03611 gold badge1616 silver badges99 bronze badges
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How can I create a Set of Sets in Python?
... answered May 9 '11 at 0:18
a3nma3nm
7,50155 gold badges2525 silver badges3737 bronze badges
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Tools for analyzing performance of a Haskell program
...our program with +RTS -s
$ time ./A +RTS -s
./A +RTS -s
749700
9,961,432,992 bytes allocated in the heap
2,463,072 bytes copied during GC
29,200 bytes maximum residency (1 sample(s))
187,336 bytes maximum slop
**2 MB** total memory in use (0 MB lost due ...
C++: Rounding up to the nearest multiple of a number
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