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Why is iterating through a large Django QuerySet consuming massive amounts of memory?
...rst time you iterate over it. For example, this will print the headline of all entries in the database:
for e in Entry.objects.all():
print e.headline
So your ten million rows are retrieved, all at once, when you first enter that loop and get the iterating form of the queryset. The wait ...
What is the JavaScript convention for no operation?
... "function" // returns true
It can be invoked as a function and essentially does nothing as shown here:
setTimeout(function() {
console.log('Start: ', Date.now());
Function.prototype();
console.log('End : ', Date.now());
}, 1000);
Although this is a "true noop" since...
Select unique or distinct values from a list in UNIX shell script
...n the following input:
class
jar
jar
jar
bin
bin
java
uniq will output all lines exactly once:
class
jar
bin
java
uniq -d will output all lines that appear more than once, and it will print them once:
jar
bin
uniq -u will output all lines that appear exactly once, and it will print them ...
What's the difference between console.dir and console.log?
... @icedwater: Depends on whether you have the console open when you call console.log or open it later. Yes, really. :-)
– T.J. Crowder
Jun 22 '17 at 17:12
...
How to get the full path of running process?
...
According to my measurements, calling process.Modules[0] is 50 times slower than calling process.MainModule.
– Luca Cremonesi
Oct 23 '14 at 16:14
...
Commonly accepted best practices around code organization in JavaScript [closed]
...ferent "namespaces" and sometimes individual classes in separate files. Usually I start with one file and as a class or namespace gets big enough to warrant it, I separate it out into its own file. Using a tool to combine all you files for production is an excellent idea as well.
...
How to get a cross-origin resource sharing (CORS) post request working
...
I finally stumbled upon this link "A CORS POST request works from plain javascript, but why not with jQuery?" that notes that jQuery 1.5.1 adds the
Access-Control-Request-Headers: x-requested-with
header to all CORS requests....
Greenlet Vs. Threads
...
Greenlets provide concurrency but not parallelism. Concurrency is when code can run independently of other code. Parallelism is the execution of concurrent code simultaneously. Parallelism is particularly useful when there's a lot of work to be done in userspace, an...
What is the fastest integer division supporting division by zero no matter what the result is?
...x, int y)
{
y += y == 0;
return x/y;
}
The compiler basically recognizes that it can use a condition flag of the test in the addition.
As per request the assembly:
.globl f
.type f, @function
f:
pushl %ebp
xorl %eax, %eax
movl %esp, %ebp
movl 12(%...
C library function to perform sort
...
qsort() is the function you're looking for. You call it with a pointer to your array of data, the number of elements in that array, the size of each element and a comparison function.
It does its magic and your array is sorted in-place. An example follows:
#include <st...