Design Patterns In Python (Book)

Your object structure inside an application may be complicated and varied. A good example is what could be created using the Composite structure. The objects that make up the hierarchy of objects, can be anything and most likely complicated to modify as your application grows. Instead, when designing the objects…

In the Template Method pattern, you create an abstract class (template) that contains a Template Method that is a series of instructions that are a combination of abstract and hook methods. Abstract methods need to be overridden in the subclasses that extend the abstract (template) class. Hook methods normally have…

The Strategy Pattern is similar to the State Pattern, except that the client passes in the algorithm that the context should run. The algorithm should be contained within a class that implements the particular strategies interface. An application that sorts data is a good example of where you can incorporate…

Not to be confused with object state, i.e., one of more attributes that can be copied as a snapshot, the State Pattern is more concerned about changing the handle of an object’s method dynamically. This makes an object itself more dynamic and may reduce the need of many conditional statements. …

Throughout the lifecycle of an application, an objects state may change. You might want to store a copy of the current state in case of later retrieval. E.g., when writing a document, you may want to auto save the current state every 10 minutes. Or you have a game, and…

The most universal approach to installing Python is to visit the official Python download page at, https://www.python.org/downloads/ Normally this page will detect your operating system from the useragent in your browser and select which install is appropriate for you. There will be 64 and 32 bit versions for your operating…

All the examples in this TypeScript Design Patterns series will be run using the Node.js runtime. All the code is written in TypeScript first and then converted into JavaScript that the Node.js runtime will further interpret and execute. So, to get started, install Node.js first. Open a browser and visit…

Objects communicate through the Mediator rather than directly with each other. As a system evolves and becomes larger and supports more complex functionality and business rules, the problem of communicating between these components becomes more complicated to understand and manage. It may be beneficial to refactor your system to centralize…

The Iterator will commonly contain two methods that perform the following concepts. next: returns the next object in the aggregate (collection, object). hasNext: returns a Boolean indicating if the Iterable is at the end of the iteration or not. The benefits of using the Iterator pattern are that the client…