Python LEGB Scope, First-Class Functions, and Common Pitfalls Explained

·2 views

A new developer guide on DEV Community breaks down several intermediate Python concepts that often confuse beginners. The article explains Python's LEGB scoping rule, which defines the order — Local, Enclosing, Global, and Built-in — in which Python resolves variable names. It also covers the use of the nonlocal keyword, which allows inner functions to modify variables belonging to an enclosing function's scope. Additional topics include first-class functions, flexible argument passing with *args and **kwargs, and the risks of using mutable objects as default function arguments. The guide aims to make these concepts approachable through simple definitions and step-by-step code examples.

Read the full story at DEV Community

This is an AI-generated summary. ShortSingh links to the original source for the complete article.

Discussion (0)

Rails 8 Upgrade Cuts Response Times 18% and Eliminates Redis Dependency

A development team migrated a mid-sized application from Rails 7 to Rails 8 and documented concrete performance improvements across multiple areas. Rails 8's Solid Queue, Solid Cache, and Solid Cable allowed the team to replace Redis and Sidekiq with database-backed alternatives, reducing infrastructure costs and operational complexity. The upgrade delivered roughly 18% faster average response times, 25% higher background job throughput, and a 15% reduction in CI pipeline duration. Asset pipeline changes via Propshaft and import maps also cut deployment compile times, while tighter Kamal 2 integration simplified zero-downtime releases. The team noted the migration required significant effort, especially around Solid Queue adoption and deprecated API audits, but concluded the gains justified the investment.

0 comments Read more at DEV Community

ProgrammingDEV Community ·

Developer Builds AI-Readable Knowledge Base Using Obsidian and Git, No RAG Pipeline Needed

A developer at NEXT4I built a structured knowledge-base system using Obsidian, Git, and VS Code to solve the problem of documentation scattered across Google Docs, Trello, Apple Notes, and multiple code repositories. The system relies entirely on plain Markdown files organized into folders covering infrastructure, platform design, principles, and other domains. Because an Obsidian vault is simply a folder of .md files, the VS Code AI agent can read it natively without any custom integration, vector database, or embedding pipeline. Version control is handled by initializing a Git repository inside the vault, enabling full decision history and audit trails via a private GitHub repo. The approach was guided by three criteria: zero vendor lock-in, offline and online accessibility, and AI-readability without additional infrastructure.

0 comments Read more at DEV Community

ProgrammingDEV Community ·

Verbose Agent Logs Are Not Audit Trails Without Evidence Contracts and Tests

AI agent runtimes can generate thousands of log lines yet still fail to answer what actions were actually taken after a failure, making true audit trails distinct from verbose logging. A reliable audit trail requires append-only events with stable run IDs, monotonically increasing sequence numbers, and a hash chain that makes tampering or omission detectable. Sensitive data such as tokens, credentials, and raw prompts must be redacted at write time rather than filtered later in a dashboard query. Each externally visible tool call should progress through defined states — from intent recorded through dispatch to confirmed or unknown outcome — with stable request keys to prevent duplicate effects during retries. The test suite must actively mutate the ledger and confirm the verifier rejects deleted, reordered, or forged records, ensuring the system fails closed rather than silently accepting corrupted evidence.

0 comments Read more at DEV Community

ProgrammingDEV Community ·

How Businesses Are Using Stablecoins for Cross-Border B2B Payments

Stablecoin-based B2B settlement refers to the use of dollar- or euro-pegged digital assets to complete transactions between companies, suppliers, and financial platforms. Unlike traditional bank transfers, blockchain networks operate around the clock and across time zones, removing dependence on banking hours or correspondent bank chains. Stablecoins can also be programmed via smart contracts to release payments automatically upon delivery confirmation or other agreed conditions. However, blockchain finalization alone does not constitute a complete settlement — businesses must also satisfy KYC/AML requirements, ensure the asset's legal recognition in their jurisdiction, and handle accounting and tax obligations correctly. The most practical use cases identified include international supplier payments, treasury operations, contractor payouts, and programmable escrow arrangements.

0 comments Read more at DEV Community