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What is more efficient? Using pow to square or just multiply it with itself?
...second parameter to pow is an int, then the std::pow(double, int) overload from <cmath> will be called instead of ::pow(double, double) from <math.h>.
This test code confirms that behavior:
#include <iostream>
namespace foo
{
double bar(double x, int i)
{
std::c...
Deep copy of a dict in python
...zable. It may help those who are only dealing with simple data structures, from an API for example, but I don't think it's enough of a solution to fully answer the OP's question.
– rob
Oct 24 '17 at 15:38
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127 Return code from $?
What is the meaning of return value 127 from $? in UNIX.
8 Answers
8
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How do I exit from the text window in Git?
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It's worth getting to know vim so you can quit it from a wide variety of applications that default to it.
– djechlin
Sep 16 '17 at 21:35
add a comment...
Constantly print Subprocess output while process is running
To launch programs from my Python-scripts, I'm using the following method:
13 Answers
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Android SQLite DB When to Close
...l prevent multiple manipulations to the database and save your application from a potential crash
so in your singleton, you might have a method like this to get your single SQLiteOpenHelper object:
private SQLiteDatabase db;
private MyDBOpenHelper mySingletonHelperField;
public MyDBOpenHelper getD...
What is DOM Event delegation?
...and code that dynamically creates new elements on the fly can be decoupled from the logic of binding their event handlers.
Another benefit to event delegation is that the total memory footprint used by event listeners goes down (since the number of event bindings go down). It may not make much of a...
Redirect to an external URL from controller action in Spring MVC
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You can use the RedirectView. Copied from the JavaDoc:
View that redirects to an absolute, context relative, or current request relative URL
Example:
@RequestMapping("/to-be-redirected")
public RedirectView localRedirect() {
RedirectView redirectView ...
When saving, how can you check if a field has changed?
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I use following mixin:
from django.forms.models import model_to_dict
class ModelDiffMixin(object):
"""
A model mixin that tracks model fields' values and provide some useful api
to know what fields have been changed.
"""
def ...
Get environment variable value in Dockerfile
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ARG is available from docker v1.9 onwards.
– Synesso
May 20 '16 at 6:02
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