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Converting JSON String to Dictionary Not List
...datapoints[0][0]). Just to list them, I tried doing datapoints[0:5][0] but all I get is the first datapoint with both elements as opposed to wanting to get the first 5 datapoints containing only the first element. Is there a way to do this?
datapoints[0:5][0] doesn't do what you're expecting. dat...
Fastest way to determine if an integer's square root is an integer
... CPU (x86) and programming language (C/C++). Your results may vary, especially because I don't know how the Java factor will play out.
My approach is threefold:
First, filter out obvious answers. This includes negative numbers and looking at the last 4 bits. (I found looking at the last six di...
Better way to sum a property value in an array
...
Updated Answer
Due to all the downsides of adding a function to the Array prototype, I am updating this answer to provide an alternative that keeps the syntax similar to the syntax originally requested in the question.
class TravellerCollection e...
Golang tests in sub-directory
...
Note that you can run go test "recursively": you need to list all the packages you want to test.
If you are in the root folder of your Go project, type:
go test ./...
The './...' notation is described in the section "Description of package lists" of the "command go":
An import path is...
Run a single migration file
...f the ruby file:
rails console
>> require "db/migrate/20090408054532_add_foos.rb"
>> AddFoos.up
Note: newer versions of rails may require AddFoos.new.up rather than AddFoos.up.
An alternative way (without IRB) which relies on the fact that require returns an array of class names:
sc...
Hook up Raspberry Pi via Ethernet to laptop without router? [closed]
I'm working on a balloon project with a Raspberry Pi. When we potentially recover the Raspberry Pi, it will most likely be in a rural location and I'd like to turn off the Pi at that point safely.
...
PHP Function with Optional Parameters
...wered Oct 20 '10 at 14:32
Matt BallMatt Ball
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...
Why does volatile exist?
...ed 16 bit value as a semaphore to know when the other guy was done. Essentially we did this:
void waitForSemaphore()
{
volatile uint16_t* semPtr = WELL_KNOWN_SEM_ADDR;/*well known address to my semaphore*/
while ((*semPtr) != IS_OK_FOR_ME_TO_PROCEED);
}
Without volatile, the optimizer sees ...
Traits vs. interfaces
...
Except that traits are not interfaces at all. Interfaces are specification that can be checked against. Traits cannot be checked against, hence they are implementation only. They are the exact opposite of interfaces. That line in the RFC is simply wrong...
...
How do you iterate through every file/directory recursively in standard C++?
...e to the standard.
An example, taken straight from the website:
bool find_file( const path & dir_path, // in this directory,
const std::string & file_name, // search for this name,
path & path_found ) // placing path here if found
{
...