Tutorial by Examples: g

Some websites don’t like to be scraped. In these cases you may need to simulate a real user working with a browser. Selenium launches and controls a web browser. from selenium import webdriver browser = webdriver.Firefox() # launch firefox browser browser.get('http://stackoverflow.com/questi...

To get a difference between two Calendars, use getTimeInMillis() method: Calendar c1 = Calendar.getInstance(); Calendar c2 = Calendar.getInstance(); c2.set(Calendar.DATE, c2.get(Calendar.DATE) + 1); System.out.println(c2.getTimeInMillis() - c1.getTimeInMillis()); //outputs 86400000 (24 * 60 * ...

"MySQL Cluster" disambiguation... NDB Cluster -- A specialized, mostly in-memory, engine. Not widely used. Galera Cluster aka Percona XtraDB Cluster aka PXC aka MariaDB with Galera. -- A very good High Availability solution for MySQL; it goes beyond Replication. See individual page...

The Error Log is populated with start and stop information, and critical events encountered by the server. The following is an example of its contents: The variable log_error holds the path to the log file for error logging. In the absence of a configuration file entry for log_error, the system...

The code draws only the wedge ... circle drawn here for perspective only. // Usage var wedge={ cx:150, cy:150, radius:100, startAngle:0, endAngle:Math.PI*.65 } drawWedge(wedge,'skyblue','gray',4); function drawWedge(w,fill,stroke,strokewidth){ ctx.beginPath(); ...

A regular polygon has all sides equal length. // Usage: drawRegularPolygon(3,25,75,50,6,'gray','red',0); drawRegularPolygon(5,25,150,50,6,'gray','gold',0); drawRegularPolygon(6,25,225,50,6,'gray','lightblue',0); drawRegularPolygon(10,25,300,50,6,'gray','lightgreen',0); function drawRegular...

adb devices Is your phone displaying? If not, enable developer mode on your phone, and connect it by USB. adb reverse tcp:8081 tcp:8081 : In order to link correctly your phone and that React-Native recognize him during build. (NOTE:Android Version 5 or above.) react-native run-andr...

Before you start the cherry-pick process, you can check if the commit you want to cherry-pick already exists in the target branch, in which case you don't have to do anything. git branch --contains <commit> lists local branches that contain the specified commit. git branch -r --contains <...

Bounded type parameters allow you to set restrictions on generic type arguments: class SomeClass { } class Demo<T extends SomeClass> { } But a type parameter can only bind to a single class type. An interface type can be bound to a type that already had a binding. This is achieve...

The common modifier to ignore case is i: /fog/i will match Fog, foG, etc. The inline version of the modifier looks like (?i). Notes: In Java, by default, case-insensitive matching assumes that only characters in the US-ASCII charset are being matched. Unicode-aware case-insensitive matching c...

The modifier that allows using whitespace inside some parts of the pattern to format it for better readability and to allow comments starting with #: /(?x)^ # start of string (?=\D*\d) # the string should contain at least 1 digit (?!\d+$) # the string cannot consist of digi...

The PCRE-compliant PCRE_UNGREEDY flag expressed with /U. It switches greediness inside a pattern: /a.*?b/U = /a.*b/ and vice versa.

One more PCRE modifier that allows the use of duplicate named groups. NOTE: only inline version is supported - (?J), and must be placed at the start of the pattern. If you use /(?J)\w+-(?:new-(?<val>\w+)|\d+-empty-(?<val>[^-]+)-collection)/ the "val" group values will be ...

With the bind command it is possible to define custom key bindings. The next example bind an Alt + w to >/dev/null 2>&1: bind '"\ew"':"\" >/dev/null 2>&1\"" If you want to execute the line immediately add \C-m (Enter) to it: bind '"\ew&quo...

When a Java virtual machine starts, it needs to know how big to make the Heap, and the default size for thread stacks. These can be specified using command-line options on the java command. For versions of Java prior to Java 8, you can also specify the size of the PermGen region of the Heap. Note...

Searching git log using some string in log: git log [options] --grep "search_string" Example: git log --all --grep "removed file" Will search for removed file string in all logs in all branches. Starting from git 2.4+, the search can be inverted using the --invert-grep...

Reading invalid UTF-8 When reading UTF-8 encoded data, it is important to be aware of the fact the UTF-8 encoded data can be invalid or malformed. Such data should usually not be accepted by your program (unless you know what you are doing). When unexpectedly encountering malformed data, different ...

The arrayref for @foo is \@foo. This is handy if you need to pass an array and other things to a subroutine. Passing @foo is like passing multiple scalars. But passing \@foo is a single scalar. Inside the subroutine: xyz(\@foo, 123); ... sub xyz { my ($arr, $etc) = @_; print $arr-&g...

Objective C NSURL *url = [NSURL URLWithString:@"YOUR URL"]; AVPlayer *player = [AVPlayer playerWithURL:videoURL]; AVPlayerLayer *playerLayer = [AVPlayerLayer playerLayerWithPlayer:player]; playerLayer.frame = self.view.bounds; [self.view.layer addSublayer:playerLayer]; [player play];...

To unregister from Remote Notifications programatically you can use Objective-C [[UIApplication sharedApplication] unregisterForRemoteNotifications]; Swift UIApplication.sharedApplication().unregisterForRemoteNotifications() this is similar to going into the setting of your phone and manual...