Tech Discoveries by M

One of the most common mistakes Python developers make is using mutable objects as default function arguments. In this following example, the default list items=[] is used as the function argument. When mutable object - list is used as function argument, the object is created once and reused  every time the function is called. This creates hidden persistent storage , where data keeps accumulating across calls. def add_items(item, items=[] ):     items.append(item)     return items print(add_items(1)) print(add_items(2)) Output [1] [1, 2] "Mutable objects should not be used as default function arguments. Instead, use None  and create the object inside the function." In this way, each function call now creates a fresh new list . def add_items(item, items= None ):     if items is None:         items = []     items.append(item)     return items print(add_items(1)) print(add_items(2)) Output [1] [2]

  Understanding Python internals is   crucial for writing bug-free code   and is a   favorite topic in technical interviews . On Day 1, we focus on how Python handles objects in memory, mutability, function arguments, and object identity. Let’s break it down step by step. 1. Mutable vs Immutable Objects in Python In Python,  everything is an object , and each object is either  mutable  or  immutable . 1a. Immutable Objects Immutable objects  cannot be changed after creation . Examples: int float str tuple and frozenset Example: Input a = 10 b = a b += 1 print(a) Output - 10 🧠  This is because   int  is immutable. When  b += 1  is executed, Python creates a  new object  for  b . a  still points to the original value  10 . 1b. Mutable Objects Mutable objects  can be modified in place . Examples: list dict set and  Most Custom Objects Example: Input a = [1, 2, 3] b = a b.append(4) prin...

  To Read - 👉🏻 Distributed Version Control System - Part 1 👈🏻 Basic Git Commands 1. Project folder အတွင်း Git repository အသစ် ဖန်တီးခြင်း      git  init 2. ရှိပြီးသား repository ကို local machine ကို copy လုပ်ခြင်း      git  clone 3. လက်ရှိ file အခြေအနေ (modified, staged, untracked) ကိုကြည့်ခြင်း      git  status 4. ပြင်ဆင်မှုများကို commit လုပ်ဖို့ stage လုပ်ခြင်း      git  add filename.py        git  add .             5. Staged changes ကို repository မှာ save လုပ်ခြင်း      git  commit 6. Local repository မှ committed changes ကို remote repository သို့ ပို့ခြင်း          git  push 7. Remote repository မှ latest changes ကို local repository သို့ ယူခြင်း      git  fetch  origin      git  pull  origin main 8. Branch များကြည့်ခြင်း သို့မဟု...

To Read -  👉🏻  Distributed Version Control System (Part 2) - Git Commands  👈🏻 Distributed Version Control System Distributed Version Control System (DVCS) ဆိုတာ source code တွေကို တစ်နေရာထဲမှာ သိမ်းဆည်းတာတင်သာမကပဲ၊ ပြင်ဆင်မှုတိုင်းကို မှတ်တမ်းတင်ပေးပြီး အဖွဲဝင်များအကြား ပူးပေါင်းလုပ်ဆောင်နိုင်စေတဲ့ စနစ်ဖြစိပါတယ်။  Distributed Version Control System (Git) - Git Hub, Git Lab, Bit Bucket, Azure Repos, ... VCS applications တွေက source code ကို သိမ်းဆည်းပေးရုံသာမက အောက်ဖော်ပြပါ features supportတွေကို လုပ်ပေးပါတယ်။ ✨ Repository  Developers တွေဟာ repository လိုခေါာတဲ့ သိုလှောင်ရုံများစွာကို ဖန်တီးနိုင်ပြီး ကိုယ်ပိုင် project တွေကို သိမ်းဆည်းထားလို့ရပါတယ်။ ✨ Collaboration  ကိုယ်ဖန်တီးထားတဲ့ repository တွေကို တခြား developers တွေကို sharing လုပ်နိုင်သလို project တစ်ခုထဲ အတူရေးနေတဲ့ developer team members တွေကို invite လုပ်ပြီး ရေးထားတဲ့ source code တွေကို repository ပေါာ အချိန်နဲ့တပြေးညီ တင်ခြင်းအားဖြင့် team တစ်ခုလုံးက ရေးထားတဲ့ codingတွေဟာ အမြဲ update ဖြစ်နေမှ...

In my previous blog, I discussed the Abstract Factory Pattern , which you can read if you're interested. Today, I am going to discuss the Factory Pattern. Factory Design Pattern Factory design pattern is similar to abstract factory pattern and they both are creational design patterns. The only difference is that Factory pattern has only one factory class while abstract factory pattern can have multiple different factories which extend the main abstract factory class. So, if you want to implement an application that have multiple similar objects, you can use factory pattern. Otherwise, if you have to implement multiple different types of objects, you can use abstract factory pattern which allows you to create multiple factories.  For Factory design pattern, it is quite less complex than abstract one. Take a look at this following diagram. I used the same example for both abstract factory and factory pattern. So you can understand the difference between two of them easily. The Factor...

 There are 5 types of creational design patterns - Abstract Factory, Builder, Factory Method, Prototype and Singleton.  Abstract Factory Design Pattern Abstract Factory is used for creation of various types of similar objects. Before explanation about the structure of this pattern, take a look at the following diagram.    The Abstract Factory Pattern may seem complex at first, but once you understand its components, it becomes much easier to work with. Here's a simple breakdown of how it operates. It consists of six key components: Interface : An interface acts as a blueprint that multiple classes will implement. In this example, Food_Drink_Interface defines a food_drink ( ) method with an empty body. This method is implemented by multiple concrete classes such as Burger , Pizza , Coffee , and Tea . Abstract Factory : An abstract factory helps create related objects without needing to know which concrete class is being instantiated. In this case, Food_Drink_Fa...