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Get last result in interactive Python shell
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Underscore.
>>> 5+5
10
>>> _
10
>>> _ + 5
15
>>> _
15
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Named routes _path vs _url
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_path helpers provide a site-root-relative path. You should probably use this most of the time.
_url helpers provide an absolute path, including protocol and server name. I've found that I mainly use these in emails when cre...
In C, do braces act as a stack frame?
...'t have to generate code that pushes/pops anything on entry/exit (and generally, they don't).
Also note that local variables may not use any stack space at all: they could be held in CPU registers or in some other auxiliary storage location, or be optimized away entirely.
So, the d array, in theor...
How to find memory leak in a C++ code/project?
...e software tools
1
Understand the operator basics. The C++ operator new allocates heap memory. The delete operator frees heap memory. For every new, you should use a delete so that you free the same memory you allocated:
char* str = new char [30]; // Allocate 30 bytes to house a string.
delete ...
Truncating all tables in a Postgres database
I regularly need to delete all the data from my PostgreSQL database before a rebuild. How would I do this directly in SQL?
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How to base64 encode image in linux bash / shell
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You need to use cat to get the contents of the file named 'DSC_0251.JPG', rather than the filename itself.
test="$(cat DSC_0251.JPG | base64)"
However, base64 can read from the file itself:
test=$( base64 DSC_0251.JPG )
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How to generate a random number in C++?
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The most fundamental problem of your test application is that you call srand once and then call rand one time and exit.
The whole point of srand function is to initialize the sequence of pseudo-random numbers with a random seed.
It means that if you pass the same value to srand in two differ...
Programmatically find the number of cores on a machine
...ne, if a system is capable of turning some off they might not be counted. Calling sysconf with "_SC_NPROCESSORS_CONF" will return the total CPUs configured.
– Chris S
Apr 23 '11 at 18:43
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Difference between left join and right join in SQL Server [duplicate]
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@SilapAliyev That's actually a very good question. Can anyone answer? :D
– Ian Chu Te
Jan 8 '16 at 2:46
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How to get position of a certain element in strings vector, to use it as an index in ints vector?
...e use size_t we must be careful not to subtract a larger iterator from a smaller iterator.
– dasblinkenlight
Oct 17 '17 at 10:49
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