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What is `related_name` used for in Django?
What is the related_name argument useful for on ManyToManyField and ForeignKey fields? For example, given the following code, what is the effect of related_name='maps' ?
...
Converting string to Date and DateTime
...6-2003');
$timestamp = $d->getTimestamp(); // Unix timestamp
$formatted_date = $d->format('Y-m-d'); // 2003-10-16
Edit: you can also pass a DateTimeZone to DateTime() constructor to ensure the creation of the date for the desired time zone, not the server default one.
...
Version number comparison in Python
...o for your cmp function:
>>> cmp = lambda x, y: StrictVersion(x).__cmp__(y)
>>> cmp("10.4.10", "10.4.11")
-1
If you want to compare version numbers that are more complex distutils.version.LooseVersion will be more useful, however be sure to only compare the same types.
>>...
How to use clock() in C++
...#include <cstdio>
#include <ctime>
int main() {
std::clock_t start;
double duration;
start = std::clock();
/* Your algorithm here */
duration = ( std::clock() - start ) / (double) CLOCKS_PER_SEC;
std::cout<<"printf: "<< duration <<'\n';
}
...
How to make PDF file downloadable in HTML link?
...ad of linking to the .PDF file, instead do something like
<a href="pdf_server.php?file=pdffilename">Download my eBook</a>
which outputs a custom header, opens the PDF (binary safe) and prints the data to the user's browser, then they can choose to save the PDF despite their browser s...
What is lexical scope?
...ipt our choices for scoping are:
as-is (no scope adjustment)
lexical var _this = this; function callback(){ console.log(_this); }
bound callback.bind(this)
It's worth noting, I think, that JavaScript doesn't really have dynamic scoping. .bind adjusts the this keyword, and that's close, but not t...
How to set default values in Rails?
...ay:
class SetDefault < ActiveRecord::Migration
def self.up
change_column :people, :last_name, :type, :default => "Doe"
end
def self.down
# You can't currently remove default values in Rails
raise ActiveRecord::IrreversibleMigration, "Can't remove the default"
end
end
Be...
What is the Swift equivalent to Objective-C's “@synchronized”?
...d on some of the code I've seen from Matt Bridges and others.
func synced(_ lock: Any, closure: () -> ()) {
objc_sync_enter(lock)
closure()
objc_sync_exit(lock)
}
Usage is pretty straight forward
synced(self) {
println("This is a synchronized closure")
}
There is one problem...
PHP - Debugging Curl
...
You can enable the CURLOPT_VERBOSE option:
curl_setopt($curlhandle, CURLOPT_VERBOSE, true);
When CURLOPT_VERBOSE is set, output is written to STDERR or the file specified using CURLOPT_STDERR. The output is very informative.
You can also use tcpdu...
Adding :default => true to boolean in existing Rails column
...dding a default boolean value to an existing column. So I tried the change_column suggestion but I mustn't be doing it right.
...