March 2021 - Page 25 of 69

How to Use Class Inheritance in Python 3 – Complete Guide 2025–2026

How to Use Class Inheritance in Python 3 – Complete Guide 2025–2026

Learning how to use class inheritance in Python 3 is one of the most powerful and frequently used concepts in object-oriented programming at Progressive Robot — inheritance lets you create new classes (child/subclasses) that inherit attributes and methods from existing classes (parent/base classes), promoting code reuse, reducing repetition, following the DRY principle, improving maintainability, and building scalable, hierarchical models for real-world applications (from simple utilities to enterprise systems, web APIs, data pipelines, game engines, and AI architectures).

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A Comparative Introduction to FreeBSD for Linux Users — step-by-step Linux tutorial on Progressive Robot

A Comparative Introduction to FreeBSD for Linux Users

FreeBSD is a free and open-source operating system that is ideal for server deployments. In this guide we will discuss some of the important differences between FreeBSD and Linux. Understanding these differences can help make the transition to FreeBSD for Linux users less of a struggle.

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Oracle Linux 8 — openssl — security and stability fixes — required update — diagnosis and fix on Oracle Linux 8

Oracle Linux 8 — openssl — security and stability fixes — required update (ELSA-2020-1840)

🟡 Medium   ⏱ 10–30 min  Last verified: 25 May 2026 Affected versions: Oracle Linux 8 📖 ~4 min read  •  Source: ELSA advisory ELSA-2020-1840 Related CVEs: CVE-2019-1563 CVE-2019-1549 CVE-2019-1547 Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification […]

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Amazon Linux 2 — inkscape — multiple vulnerabilities (3 CVEs) — patch and remediation guide — diagnosis and fix on Amazon Linux 2

Amazon Linux 2 — inkscape — multiple vulnerabilities (3 CVEs) — patch and remediation guide

🟡 Medium   ⏱ 10–30 min  Last verified: 25 May 2026 Affected versions: Amazon Linux 2 📖 ~4 min read  •  Source: Amazon Linux advisory ALAS2-2023-2043 Related CVEs: CVE-2021-42700 CVE-2021-42702 CVE-2021-42704 Upstream summary: Inkscape 0.91 is vulnerable to an out-of-bounds read, which may allow an attacker to have access to unauthorized information. (CVE-2021-42700) Inkscape version […]

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Common Problems 115995

UFW Blocking SSH or Required Service Ports

🟡 Medium   ⏱ 5–30 min  Last verified: 19 May 2026 📖 ~1 min read Table of contents Symptom & Impact Environment & Reproduction Root Cause Analysis Quick Triage Step-by-Step Diagnosis Solution – Primary Fix Solution – Alternative Approaches Verification & Acceptance Criteria Rollback Plan Prevention & Hardening Related Errors & Cross-Refs References & Further […]

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How to Install Neo4j on Oracle Linux 8 — step-by-step Oracle Linux 8 tutorial on Progressive Robot

How to Install Neo4j on Oracle Linux 8

Introduction Oracle Linux 8 ships with a stable, security-hardened base that makes deploying install neo4j on oracle linux 8 both straightforward and auditable. This tutorial covers the complete procedure for how to Install Neo4j on Oracle Linux 8, including dnf module streams where applicable, systemd unit management, and the firewalld rules required for network-facing services. […]

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Ubuntu 18.04 — pygments — multiple vulnerabilities (2 CVEs) — patch and remediation guide — diagnosis and fix on Ubuntu 18.04

Ubuntu 18.04 — pygments — multiple vulnerabilities (2 CVEs) — patch and remediation guide

🟢 Low   ⏱ 5–15 min  Last verified: 25 May 2026 Affected versions: Ubuntu 18.04 (bionic) 📖 ~4 min read  •  Source: Ubuntu Security Notice USN-4897-1 Related CVEs: CVE-2021-27291 CVE-2021-20270 Upstream summary: Ben Caller discovered that Pygments incorrectly handled parsing certain files. If a user or automated system were tricked into parsing a specially crafted […]

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