Python Functions: Parameters, Return Values, and Scope Parameter Passing in Python In Python, function parameters are passed by value. This means that when a function is called, the values of the actual parameters are copied to the formal parameters. Any modifications made to these parameters inside...
Runtime Polymorphism Foundation Virtual member funcsions enable dynamic dispatch by deferring method resolution until execution time. Instead of relying on the declared type, the compiler routes invocations through a per-class lookup structure known as the virtual table. This arrangement allows deri...
Least squares fitting is a fundamental technique in regression analysis used to approximate the solution of overdetermined systems. Given a dataset of experimental points $(x_i, y_i)$ that are expected to follow a specific functional relationship $y = f(x, \mathbf{p})$, the primary goal is to determ...
Extending Built-in Immutable Types with Custom Instantiation Problem Scenario We need to create a custom tuple variant that filters an iterable to retain only positive integer values: FilteredTuple([1, -1, 'abc', 6, ['x', 'y'], 3]) => (1, 6, 3) Solution Override the __new__ method to intercept ob...
In Django, an application (app) is a self-contained module that implements specific website functionality.Apps help organize project code into reusable, modular components. For instance, you might create an "articles" app for blog posts, a "users" app for authentication, or a &qu...
Nginx is a lightweight, high-performance web server and reverse proxy server developed by Igor Sysoev from Russia. It excels in handling high concurrency, with reports indicating support for up to 50,000 simultaneous connections. Nginx Features Nginx is widely adopted in internet projects due to sev...
Atomicity An atomic operation is one that is executed as a single, indivisible unit. The operation either completes entirely or not at all. Atomicity Issues in Multithreading Consider a scenario where we want 100 threads to each deliver 100 flowers to Xiao Ha, but we find that the total is less than...
Network traffic filtering on RHEL-based distributions is handled by firewalld, which organizes rules into zones and requires explicit synchronization between permanent and runtime configurations. Verify the daemon's current state: systemctl is-active firewalld Initialize the service and configure it...
Command History Auditing Enabling command history with timestamps and increasing the history size provides visibility into system operations. This helps track user activiites and troubleshoot issues: # /etc/profile.d/history_config.sh export HISTSIZE=10000 export HISTTIMEFORMAT="%Y-%m-%d %H:%M:...
A Python virtual enviroment is an isolated copy of the original Python installation. It allows you to manage project-specific dependencies without interfering with the system-wide Python setup. The virtual environment is essentially a copy of the base environment, as illustrated below: The Lib direc...
