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mongo group query how to keep fields
...are accumulated/funneled/reduced) doesn't make so much sense even theoretically. However, sorting before hand is actually inefficient compared to sorting each group within themselves since sorting algorithms are more complex than O(n). I wish there would be better ways in MongoDB.
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How to calculate a time difference in C++
...turns the CPU time consumed by the program. So if the program is run in parallel the time returned by the function would be the accumulated of the time spent on all CPUs, rather than the time elapsed cplusplus.com/reference/ctime/clock
– Ameer Jewdaki
Aug 3 '1...
In Python, how do I read the exif data for an image?
...e. Some images are generated without EXIF data. If it is empty programmatically, try opening the image file in a photo editing software to check if it actually has EXIF data.
– Gino Mempin
Sep 6 at 0:03
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lodash multi-column sortBy descending
...dash.com/docs#orderBy) in Lodash as of 4.3.0. The normal sort function is called _.sortBy(lodash.com/docs#sortBy)
– Nidhin David
Feb 12 '16 at 11:19
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Django rest framework, use different serializers in the same ModelViewSet
... like to provide two different serializers and yet be able to benefit from all the facilities of ModelViewSet :
6 Answers
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How do I view the SQL generated by the Entity Framework?
... redirecting to Immediate (Tools > Options > Debugging > Redirect all Output Window text to Immediate Window)
– rkawano
May 21 '14 at 17:41
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How to determine CPU and memory consumption from inside a process?
... quite a while, perhaps I've been only a bit stupid...)
Note: for clarity all error checking has been omitted from the following code. Do check the return codes...!
Total Virtual Memory:
#include "windows.h"
MEMORYSTATUSEX memInfo;
memInfo.dwLength = sizeof(MEMORYSTATUSEX);
GlobalMemoryStatus...
How can I quickly sum all numbers in a file?
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For a Perl one-liner, it's basically the same thing as the awk solution in Ayman Hourieh's answer:
% perl -nle '$sum += $_ } END { print $sum'
If you're curious what Perl one-liners do, you can deparse them:
% perl -MO=Deparse -nle '$sum += $_ } END ...
What do the terms “CPU bound” and “I/O bound” mean?
...U (doing calculations). A program that computes new digits of π will typically be CPU-bound, it's just crunching numbers.
A program is I/O bound if it would go faster if the I/O subsystem was faster. Which exact I/O system is meant can vary; I typically associate it with disk, but of course networ...
What is the _snowman param in Ruby on Rails 3 forms for?
...net Explorer (5, 6, 7 and 8) to encode its parameters as unicode.
Specifically, this bug can be triggered if the user switches the browser's encoding to Latin-1. To understand why a user would decide to do something seemingly so crazy, check out this google search. Once the user has put the web-sit...