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A shallow copy is a copy of a collection without performing a copy of its elements. >>> import copy >>> c = [[1,2]] >>> d = copy.copy(c) >>> c is d False >>> c[0] is d[0] True

If you have nested lists, it is desireable to clone the nested lists as well. This action is called deep copy. >>> import copy >>> c = [[1,2]] >>> d = copy.deepcopy(c) >>> c is d False >>> c[0] is d[0] False

You can create shallow copies of lists using slices. >>> l1 = [1,2,3] >>> l2 = l1[:] # Perform the shallow copy. >>> l2 [1,2,3] >>> l1 is l2 False

In functional programming languages like F# null values are considered potentially harmful and poor style (non-idiomatic). Consider this C# code: string x = SomeFunction (); int l = x.Length; x.Length will throw if x is null let's add protection: string x = SomeFunction (); int l = x ...

Box Collider A primitive Collider shaped like a cuboid. Properties Is Trigger - If ticked, the Box Collider will ignore physics and become a Trigger Collider Material - A reference, if specified, to the physics material of the Box Collider Center - The Box Collider's central posit...

I create a file called database-servlet.xml somewhere on the classpath. Initially your config file will look like this: <?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/...

One of the great things about Linq is that it is so easy to extend. You just need to create an extension method whose argument is IEnumerable<T>. public namespace MyNamespace { public static class LinqExtensions { public static IEnumerable<List<T>> Batch<T&...

To print a user-readable error message to stderr, call perror from <stdio.h>. int main(int argc, char *argv[]) { FILE *fout; if ((fout = fopen(argv[1], "w")) == NULL) { perror("fopen: Could not open file for writing"); return EXIT_FAILURE; } r...

Active Patterns can be used to make calling some .NET API's feel more natural, particularly those that use an output parameter to return more than just the function return value. For example, you'd normally call the System.Int32.TryParse method as follows: let couldParse, parsedInt = System.Int32....

One of the easiest examples of using shared services is when we want to store some data from a given page of our application, and then get that data again but from another page. One option could be to send that data as a parameter (for instance, if one page calls the other one) but if we want to us...

Anonymous class listener Before Java 8, it’s very common that an anonymous class is used to handle click event of a JButton, as shown in the following code. This example shows how to implement an anonymous listener within the scope of btn.addActionListener. JButton btn = new JButton("My Butto...

response = requests.get("https://api.github.com/events") text_resp = response.text JSON response: for json-formatted responses the package provides a built-in decoder response = requests.get('https://api.github.com/events') json_resp = response.json() This method will raise a Valu...

In Visual Studio go to your Solution Explorer then click on Project you will be adding model Right mouse. Choose ADO.NET Entity Data Model Then choose Generate from database and click Next in next window click New Connection... and point to the database you want to generate model from (Could be M...

We can use $q to defer operations to the future while having a pending promise object at the present, by using $q.defer we create a promise that will either resolve or reject in the future. This method is not equivalent of using the $q constructor, as we use $q.defer to promisify an existing routin...

Sometimes you would like to change main WordPress query. Filter pre_get_posts is the way to go. For example using pre_get_posts you can tell main loop to show only 5 posts. Or to show posts only from one category, or excluding any category etc. add_action( 'pre_get_posts', 'my_callback_function' ...

All we need to do is to use set() method of $query object. It takes two arguments, first what we want to set and second what value to set. add_action( 'pre_get_posts', 'change_posts_per_page' ); function change_posts_per_page( $query ) { if( !$query->is_main_query() || is_admin() ) retu...

DECLARE @xmlIN XML = '<TableData> <aaa Main="First"> <row name="a" value="1" /> <row name="b" value="2" /> <row name="c" value="3" /> </aaa> <aaa Main="Second"> &l...

Continuing on the mtcars example, here is a simple way to produce a plot of your linear regression that is potentially suitable for publication. First fit the linear model and fit <- lm(mpg ~ wt, data = mtcars) Then plot the two variables of interest and add the regression line within the d...

Encoding //convert the image to NSData first let imageData:NSData = UIImagePNGRepresentation(image)! // convert the NSData to base64 encoding let strBase64:String = imageData.base64EncodedStringWithOptions(.Encoding64CharacterLineLength) Decoding let dataDecoded:NSData = NSData(base64Encoded...

Let's say we have type ENUM('fish','mammal','bird') An alternative is type TINYINT UNSIGNED plus CREATE TABLE AnimalTypes ( type TINYINT UNSIGNED NOT NULL AUTO_INCREMENT, name VARCHAR(20) NOT NULL COMMENT "('fish','mammal','bird')", PRIMARY KEY(type), INDEX(na...