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unique drops duplicates so that each element in the result is unique (only appears once): x = c(2, 1, 1, 2, 1) unique(x) # 2 1 Values are returned in the order they first appeared. duplicated tags each duplicated element: duplicated(x) # FALSE FALSE TRUE TRUE TRUE anyDuplicated(x) >...

To count how many elements of two sets overlap, one could write a custom function: xtab_set <- function(A, B){ both <- union(A, B) inA <- both %in% A inB <- both %in% B return(table(inA, inB)) } A = 1:20 B = 10:30 xtab_set(A, B) # inB ...

Imagine you have the following HTML: <div> <label>Name:</label> John Smith </div> And you need to locate the text "John Smith" after the label element. In this case, you can locate the label element by text and then use .next_sibling property: from ...

BeautifulSoup has a limited support for CSS selectors, but covers most commonly used ones. Use select() method to find multiple elements and select_one() to find a single element. Basic example: from bs4 import BeautifulSoup data = """ <ul> <li class="item&quo...

Sometimes it's necessary to be able to extract values from an object using only references (ie. without transferring ownership). struct Token { pub id: u32 } struct User { pub token: Option<Token> } fn main() { // Create a user with an arbitrary token let user = User...

Let's say we have the following data: >>> data = {"cats": [{"name": "Tubbs", "color": "white"}, {"name": "Pepper", "color": "black"}]} Just dumping this as JSON does not do anything special here: ...

Have a table NameAgeCityBob10ParisMat20BerlinMary24Prague select Name from table where Age>10 AND City='Prague' Gives NameMary select Name from table where Age=10 OR City='Prague' Gives NameBobMary

Unlike the list, which is a sequential data structure, and the vector, which is both sequential and associative, the map is exclusively an associative data structure. A map consists of a set of mappings from keys to values. All keys are unique, so maps support "constant"-time lookup from k...

For if you have to fine-tune what is published. import { Mongo } from 'meteor/mongo'; import { Meteor } from 'meteor/meteor'; import { Random } from 'meteor/random'; if (Meteor.isClient) { // established this collection on the client only. // a name is required (first parameter) and this...

On the server, you can create a publication like this. this.userId is the id of the user who is currently logged in. If no user is logged in, you might want to throw an error and respond to it. import Secrets from '/imports/collections/Secrets'; Meteor.publish('protected_data', function () { ...

Swift 3 let stackView = UIStackView() stackView.axis = .horizontal stackView.alignment = .fill // .leading .firstBaseline .center .trailing .lastBaseline stackView.distribution = .fill // .fillEqually .fillProportionally .equalSpacing .equalCentering let label = UILabel() label.text = "...

Swift let stackView = UIStackView() stackView.axis = .Vertical stackView.alignment = .Fill // .Leading .FirstBaseline .Center .Trailing .LastBaseline stackView.distribution = .Fill // .FillEqually .FillProportionally .EqualSpacing .EqualCentering let label = UILabel(frame: CGRectZero) label....

You can take a snapshot from a UIView like this: Swift let snapshot = view.snapshotView(afterScreenUpdates: true) Objective-C UIView *snapshot = [view snapshotViewAfterScreenUpdates: YES];

Using the dateutil library as in the previous example on parsing timezone-aware timestamps, it is also possible to parse timestamps with a specified "short" time zone name. For dates formatted with short time zone names or abbreviations, which are generally ambiguous (e.g. CST, which coul...

You can commit changes made to specific files and skip staging them using git add: git commit file1.c file2.h Or you can first stage the files: git add file1.c file2.h and commit them later: git commit

The boolean type cannot be cast to/from any other primitive type. A char can be cast to/from any numeric type by using the code-point mappings specified by Unicode. A char is represented in memory as an unsigned 16-bit integer value (2 bytes), so casting to byte (1 byte) will drop 8 of those bits (...

Numeric primitives can be cast in two ways. Implicit casting happens when the source type has smaller range than the target type. //Implicit casting byte byteVar = 42; short shortVar = byteVar; int intVar = shortVar; long longVar = intvar; float floatVar = longVar; double doubleVar = floatVar...

For cases when we don't want to write special classes to handle some resource, we may write a generic class: template<typename Function> class Finally final { public: explicit Finally(Function f) : f(std::move(f)) {} ~Finally() { f(); } // (1) See below Finally(const Final...

It is possible to extract a date out of a text using the dateutil parser in a "fuzzy" mode, where components of the string not recognized as being part of a date are ignored. from dateutil.parser import parse dt = parse("Today is January 1, 2047 at 8:21:00AM", fuzzy=True) pr...

Although it is possible to create a fragment constructor with parameters, Android internally calls the zero-argument constructor when recreating fragments (for example, if they are being restored after being killed for Android's own reasons). For this reason, it is not advisable to rely on a constru...