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filter (python 3.x) and ifilter (python 2.x) return a generator so they can be very handy when creating a short-circuit test like or or and: Python 2.x2.0.1 # not recommended in real use but keeps the example short: from itertools import ifilter as filter Python 2.x2.6.1 from future_built...

There is a complementary function for filter in the itertools-module: Python 2.x2.0.1 # not recommended in real use but keeps the example valid for python 2.x and python 3.x from itertools import ifilterfalse as filterfalse Python 3.x3.0.0 from itertools import filterfalse which works...

First, install Node.js for your platform. In this example we'll create an HTTP server listening on port 1337, which sends Hello, World! to the browser. Note that, instead of using port 1337, you can use any port number of your choice which is currently not in use by any other service. The http mod...

[0-9] and \d are equivalent patterns (unless your Regex engine is unicode-aware and \d also matches things like ②). They will both match a single digit character so you can use whichever notation you find more readable. Create a string of the pattern you wish to match. If using the \d notation, you...

You can have multiple versions of Xcode installed at the same time (including beta versions). Simply rename the application in Finder to avoid conflicts. Note: Installing Xcode from the App Store will tend to overwrite an existing version on your machine. You can also install Xcode from a direct ...

CREATE TABLE HR_EMPLOYEES ( PersonID int, LastName VARCHAR(30), FirstName VARCHAR(30), Position VARCHAR(30) ); CREATE TABLE FINANCE_EMPLOYEES ( PersonID INT, LastName VARCHAR(30), FirstName VARCHAR(30), Position VARCHAR(30) ); Let's say we want to ...

CSS enclosed in <style></style> tags within an HTML document functions like an external stylesheet, except that it lives in the HTML document it styles instead of in a separate file, and therefore can only be applied to the document in which it lives. Note that this element must be insid...

Using the Cars Table, we will calculate the total, max, min and average amount of money each costumer spent and haw many times (COUNT) she brought a car for repairing. Id CustomerId MechanicId Model Status Total Cost SELECT CustomerId, SUM(TotalCost) OVER(PARTITION BY Cust...

When the Repeater is Bound, for each item in the data, a new table row will be added. <asp:Repeater ID="repeaterID" runat="server" OnItemDataBound="repeaterID_ItemDataBound"> <HeaderTemplate> <table> <thead> ...

This is an example of dereferencing a NULL pointer, causing undefined behavior. int * pointer = NULL; int value = *pointer; /* Dereferencing happens here */ A NULL pointer is guaranteed by the C standard to compare unequal to any pointer to a valid object, and dereferencing it invokes undefined...

int foo(void) { /* do stuff */ /* no return here */ } int main(void) { /* Trying to use the (not) returned value causes UB */ int value = foo(); return 0; } When a function is declared to return a value then it has to do so on every possible code path through it. Undefined beh...

The type of the literal Prelude> :t 1 1 :: Num a => a choosing a concrete type with annotations You can specify the type as long as the target type is Num with an annotation: Prelude> 1 :: Int 1 it :: Int Prelude> 1 :: Double 1.0 it :: Double Prelude> 1 :: Word 1 it :: ...

The type of the literal Prelude> :t 1.0 1.0 :: Fractional a => a Choosing a concrete type with annotations You can specify the type with a type annotation. The only requirement is that the type must have a Fractional instance. Prelude> 1.0 :: Double 1.0 it :: Double Prelude> 1....

A function can optionally declare a set of parameters: func SayHelloToMe(firstName, lastName string, age int) { fmt.Printf("Hello, %s %s!\n", firstName, lastName) fmt.Printf("You are %d", age) } Notice that the type for firstName is omitted because it is identical ...

The filter() method accepts a test function, and returns a new array containing only the elements of the original array that pass the test provided. // Suppose we want to get all odd number in an array: var numbers = [5, 32, 43, 4]; 5.1 var odd = numbers.filter(function(n) { return n % 2 !=...

PorterDuff.Mode is used to create a PorterDuffColorFilter. A color filter modifies the color of each pixel of a visual resource. ColorFilter filter = new PorterDuffColorFilter(Color.BLUE, PorterDuff.Mode.SRC_IN); The above filter will tint the non-transparent pixels to blue color. The color fil...

An Xfermode (think "transfer" mode) works as a transfer step in drawing pipeline. When an Xfermode is applied to a Paint, the pixels drawn with the paint are combined with underlying pixels (already drawn) as per the mode: paint.setColor(Color.BLUE); paint.setXfermode(new PorterDuffXferm...

A simple literal function, printing Hello! to stdout: package main import "fmt" func main() { func(){ fmt.Println("Hello!") }() } play it on playground A literal function, printing the str argument to stdout: package main import "fmt&quot...

Warning: be sure you have at least 15 GB of free disk space. Compilation in Ubuntu >=13.04 Option A) Use Git Use git if you want to stay in sync with the latest Ubuntu kernel source. Detailed instructions can be found in the Kernel Git Guide. The git repository does not include necessary ...

In order to test the beginning and ending of a given string in Python, one can use the methods str.startswith() and str.endswith(). str.startswith(prefix[, start[, end]]) As it's name implies, str.startswith is used to test whether a given string starts with the given characters in prefix. >...