Tutorial by Examples: n

If you put your commonly used aliases into an .iex.exs file at the root of your app, IEx will load them for you on startup. alias App.{User, Repo}
Say you have a <textarea> and you want to retrieve info about the number of: Characters (total) Characters (no spaces) Words Lines function wordCount( val ){ var wom = val.match(/\S+/g); return { charactersNoSpaces : val.replace(/\s+/g, '').length, characte...
Salt can be installed via : salt-bootstrap: a shell script, that can install salt (client and/or master packages) on standard Unix/Linux platform, Platform Specific binaries: available for Windows, Mac OS X and Linux, Package Management systems: available for pacman, apt-get, yum and other pack...
TreeWalker is a generator-like interface that makes recursively filtering nodes in a DOM tree easy and efficient. The following code concatenates the value of all Text nodes in the page, and prints the result. let parentNode = document.body; let treeWalker = document.createTreeWalker(parentNode, ...
Stored procedures can be created through a database management GUI (SQL Server example), or through a SQL statement as follows: -- Define a name and parameters CREATE PROCEDURE Northwind.getEmployee @LastName nvarchar(50), @FirstName nvarchar(50) AS -- Define the query to be...
Remarks Every motion can be used after an operator command, so the command operates on the text comprised by the movement's reach. Just like operator commands, motions can include a count, so you can move by 2words, for example. Arrows In Vim, normal arrow/cursor keys (←↓↑→) work as expected...
Horizontally vim -o file1.txt file2.txt Vertically vim -O file1.txt file2.txt You may optionally specify the number of splits to open. The following example opens two horizontal splits and loads file3.txt in a buffer: vim -o2 file1.txt file2.txt file3.txt
You are allowed to implement custom exceptions that can be thrown just like any other exception. This makes sense when you want to make your exceptions distinguishable from other errors during runtime. In this example we will create a custom exception for clear handling of problems the application ...
In normal mode: ~ inverts the case of the character under the cursor, gu{motion} lowercases the text covered by {motion}, gU{motion} uppercases the text covered by {motion} Example (^ marks the cursor position): Lorem ipsum dolor sit amet. ^ Lorem ipSum dolor sit amet. ~ Lorem...
So, you make first a .war file let's say a portlet of name <YOUR PLUGIN>.war. You wanna have it running on a glassfish domain under Liferay portal. Steps to success: Navigate to Control Panel -> Plugins Installation on Liferay Hit Install new portlets Hit Configuration Fill in to Dep...
Before to launch you to code with Pug, you need to have some prerequisits. You will need to install: NodeJS with NPM ExpressJS (optional) After installing NodeJS, you can check in your terminal the correct installation doing: $ node -v If successful, it will print the number of Node's ve...
Summary This goal is to reorganize all of your scattered commits into more meaningful commits for easier code reviews. If there are too many layers of changes across too many files at once, it is harder to do a code review. If you can reorganize your chronologically created commits into topical com...
The History Microsoft windows is an operating system available in 137 languages, wrote in C,C++ & Assembly , can be installed on "ARM, IA-32, Itanium, x86-64, DEC Alpha, MIPS, PowerPC" platforms first release was in November 20 ,1985 as windows 1.0 with about 2 billion PC(per...
Itertools "islice" allows you to slice a generator: results = fetch_paged_results() # returns a generator limit = 20 # Only want the first 20 results for data in itertools.islice(results, limit): print(data) Normally you cannot slice a generator: def gen(): n = 0 wh...
If your code encounters a condition it doesn't know how to handle, such as an incorrect parameter, it should raise the appropriate exception. def even_the_odds(odds): if odds % 2 != 1: raise ValueError("Did not get an odd number") return odds + 1
Use try...except: to catch exceptions. You should specify as precise an exception as you can: try: x = 5 / 0 except ZeroDivisionError as e: # `e` is the exception object print("Got a divide by zero! The exception was:", e) # handle exceptional case x = 0 final...
Sometimes, you may want something to occur regardless of whatever exception happened, for example, if you have to clean up some resources. The finally block of a try clause will happen regardless of whether any exceptions were raised. resource = allocate_some_expensive_resource() try: do_stu...
Sometimes you want to catch an exception just to inspect it, e.g. for logging purposes. After the inspection, you want the exception to continue propagating as it did before. In this case, simply use the raise statement with no parameters. try: 5 / 0 except ZeroDivisionError: print(&quo...
In the process of handling an exception, you may want to raise another exception. For example, if you get an IOError while reading from a file, you may want to raise an application-specific error to present to the users of your library, instead. Python 3.x3.0 You can chain exceptions to show how t...
Exception handling occurs based on an exception hierarchy, determined by the inheritance structure of the exception classes. For example, IOError and OSError are both subclasses of EnvironmentError. Code that catches an IOError will not catch an OSError. However, code that catches an EnvironmentErr...

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