Tutorial by Examples: le

This example shows you a minimal way to create a Hello World page in Django. This will help you realize that the django-admin startproject example command basically creates a bunch of folders and files and that you don't necessarily need that structure to run your project. Create a file called ...

Any value in Clojure is considered truthy unless it is false or nil. You can find the truthiness of a value with (boolean value). You can find the truthiness of a list of values using (or), which returns true if any arguments are truthy, or (and) which returns true if all arguments are truthy. =&gt...

Given items as (value, weight) we need to place them in a knapsack (container) of a capacity k. Note! We can break items to maximize value! Example input: values[] = [1, 4, 5, 2, 10] weights[] = [3, 2, 1, 2, 4] k = 8 Expected output: maximumValueOfItemsInK = 20; Algorithm: 1) Sort values...

Basic error handling should be added to all procedures in production code, since otherwise an unexpected error will cause Access to crash or invite the end-user to enter debug mode. A typical pattern for a basic error handler that traps all errors is: Sub Name() On Error GoTo errHandler '[some...

Use the makemigrations --name <your_migration_name> option to allow naming the migrations(s) instead of using a generated name. python manage.py makemigrations --name <your_migration_name> <app_name>

Opening Generic ASCII Text Files 5.6.0 open my $filehandle, '<', $name_of_file or die "Can't open $name_of_file, $!"; This is the basic idiom for "default" File IO and makes $filehandle a readable input stream of bytes, filtered by a default system-specific decoder, which...

Setting encoding with open() When opening a text file, you may specify it's encoding explicitly with a three-argument open(). This en-/decoder attached to a file handle is called an "I/O layer": my $filename = '/path/to/file'; open my $fh, '<:encoding(utf-8)', $filename or die "...

If we need to parse a large file, e.g. a CSV more than 10 Mbytes containing millions of rows, some use file or file_get_contents functions and end up with hitting memory_limit setting with Allowed memory size of XXXXX bytes exhausted error. Consider the following source (top-1m.csv has exactly...

The Salesforce application consists of several products which can be integrated with each other: Sales Cloud Marketing Page, Salesforce Documentation Service Cloud Marketing Page, Salesforce Documentation, Trailhead Marketing Cloud Marketing Page Community Cloud Marketing Page, Salesforce Do...

LeakCanary is an Open Source Java library to detect memory leaks in your debug builds. Just add the dependencies in the build.gradle: dependencies { debugCompile 'com.squareup.leakcanary:leakcanary-android:1.5.1' releaseCompile 'com.squareup.leakcanary:leakcanary-android-no-op:1.5.1' ...

static and templates folder in the apps may should also contain a folder with the name of app ex. blog this is a convention used to prevent namespace pollution, so we reference the files like /blog/base.html rather than /base.html which provides more clarity about the file we are referencing and pre...

In order for a program to react to a certain signal, other than using default action, custom signal handler can be installed using sigaction. sigaction receives three arguments - signal to act on, pointer to sigaction_t structure which, if not NULL, is describing new behaviour and pointer to sigacti...

Least squares is a standard approach to problems with more equations than unknowns, also known as overdetermined systems. Consider the four equations: x0 + 2 * x1 + x2 = 4 x0 + x1 + 2 * x2 = 3 2 * x0 + x1 + x2 = 5 x0 + x1 + x2 = 4 We can express this as a matrix multiplication A * x = b: A ...

There are several packages that allow the output of data structures in form of HTML or LaTeX tables. They mostly differ in flexibility. Here I use the packages: knitr xtable pander For HTML documents --- title: "Printing Tables" author: "Martin Schmelzer" date: &quot...

C++ thrives on what is known as a Regular type (or at least Pseudo-Regular). A Regular type is a type that can be constructed and assigned-to and assigned-from via copy or move, can be destroyed, and can be compared equal-to. It can also be constructed from no arguments. Finally, it also has supp...

Mockito offers a one-size-fits-all mehtod to create mocks of (non-final) classes and interfaces. Dependency mock = Mockito.mock(Dependency.class); This creates a mock instance of Dependency regardless of whether Dependency is a interface or class. It is then possible to stub method calls to tha...

module.exports.routes = { // This function will be executed for all http verbs on all urls 'all /*', function (req, res, next) { // Expose the function `fooBar` to all views (via the locals object) res.locals.fooBar = function (arg1) { return 'foobar' + arg1; }; }, };...

Visitor pattern allows you to add new operations or methods to a set of classes without modifying the structure of those classes. This pattern is especially useful when you want to centralise a particular operation on an object without extending the object Or without modifying the object. UML diag...

Database connections are set up using the CF Administrator tool. See Database Connections for how to connect a datasource. To execute queries all you need is the <cfquery> tag. The <cfquery> tag connects to and opens the database for you, all you need to do is supply it with the name of...

If you want to make internal classes or functions of an assembly accessable from another assembly you declare this by InternalsVisibleTo and the assembly name that is allowed to access. In this example code in the assembly MyAssembly.UnitTests is allowed to call internal elements from MyAssembly. ...