There are multiple threads in your code and you need to safely communicate between them.
You can use a Queue from the queue library.
from queue import Queue
from threading import Thread
# create a data producer
def producer(output_queue):
while True:
data = data_computation()
...
In this approach, the single is accessed via the static method:
Singleton.getInstance();
To enforce only one instance of the singleton, a private static variable retains the instance, while any additional attempts to instantiate an instance are enforced within the constructor.
package {
publ...
Cocoa is Apple's API to develop apps for macOS, formerly known as OS X.
Cocoa is a container framework, and contains three sub-frameworks.
Foundation
AppKit
CoreData
Cocoa Touch is Apple's version of Cocoa to develop apps for iOS, watchOS and tvOS.
Cocoa Touch contains the same sub-framewo...
Save the current state of working directory and the index (also known as the staging area) in a stack of stashes.
git stash
To include all untracked files in the stash use the --include-untracked or -u flags.
git stash --include-untracked
To include a message with your stash to make it more ...
The background-attachment property sets whether a background image is fixed or scrolls with the rest of the page.
body {
background-image: url('img.jpg');
background-attachment: fixed;
}
ValueDescriptionscrollThe background scrolls along with the element. This is default.fixedThe backgro...
The background-repeat property sets if/how a background image will be repeated.
By default, a background-image is repeated both vertically and horizontally.
div {
background-image: url("img.jpg");
background-repeat: repeat-y;
}
Here's how a background-repeat: repeat-y looks lik...
Multiple rows can be inserted with a single insert command:
INSERT INTO tbl_name (field1, field2, field3)
VALUES (1,2,3), (4,5,6), (7,8,9);
For inserting large quantities of data (bulk insert) at the same time, DBMS-specific features and recommendations exist.
MySQL - LOAD DATA INFILE
MSSQL - B...
If you need a completely customized view, you'll need to subclass View (the superclass of all Android views) and provide your custom sizing (onMeasure(...)) and drawing (onDraw(...)) methods:
Create your custom view skeleton: this is basically the same for every custom view. Here we create the...
Custom views can also take custom attributes which can be used in Android layout resource files. To add attributes to your custom view you need to do the following:
Define the name and type of your attributes: this is done inside res/values/attrs.xml (create it if necessary). The following file...
Unlike many other programming languages, the throw and catch keywords are not related to exception handling in Ruby.
In Ruby, throw and catch act a bit like labels in other languages. They are used to change the control flow, but are not related to a concept of "error" like Exceptions are...
This is how to create a basic method that logs 'Hello World" to the console:
- (void)hello {
NSLog(@"Hello World");
}
The - at the beginning denotes this method as an instance method.
The (void) denotes the return type. This method doesn't return anything, so you enter void.
...
Defining Strings in the strings.xml file also allows for string formatting. The only caveat is that the String will need to be dealt with in code like below, versus simply attaching it to a layout.
<string name="welcome_trainer">Hello Pokémon Trainer, %1$s! You have caught %2$d Poké...
You can create a CALayer and set its frame like this:
Swift:
let layer = CALayer()
layer.frame = CGRect(x: 0, y: 0, width: 60, height: 80)
Objective-C:
CALayer *layer = [[CALayer alloc] init];
layer.frame = CGRectMake(0, 0, 60, 80);
You can then add it as a sublayer to an existing CALayer...
To add a method to a button, first create an action method:
Objective-C
-(void)someButtonAction:(id)sender {
// sender is the object that was tapped, in this case its the button.
NSLog(@"Button is tapped");
}
Swift
func someButtonAction() {
print("Button is tapped...
You can easily transform every component in a clickable button using the MouseArea component. The code below displays a 360x360 window with a button and a text in the center; pressing the button will change the text:
import QtQuick 2.0
Rectangle {
width: 360
height: 360
Rectang...
Filters can either be defined in a method and then added to Jinja's filters dictionary, or defined in a method decorated with Flask.template_filter.
Defining and registering later:
def format_datetime(value, format="%d %b %Y %I:%M %p"):
"""Format a date time to (Defau...
It is also possible to write a context manager using generator syntax thanks to the contextlib.contextmanager decorator:
import contextlib
@contextlib.contextmanager
def context_manager(num):
print('Enter')
yield num + 1
print('Exit')
with context_manager(2) as cm:
# the ...
