Jul 20, 2022
python
Understanding Python’s asyncio architecture is crucial for writing efficient asynchronous code. Here’s a comprehensive guide.
Event Loop The event loop is the core of asyncio. It manages and distributes the execution of different tasks.
import asyncio async def main(): print("Hello") await asyncio.sleep(1) print("World") # Event loop runs the coroutine asyncio.run(main()) Coroutines Coroutines are functions defined with async def. They can be paused and resumed.
async def fetch_data(): await asyncio.sleep(1) return "data" # Coroutine object coro = fetch_data() Tasks Tasks wrap coroutines and schedule them on the event loop.
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ReadJun 15, 2022
python
Learn how to build a simple blog application using Python and Flask.
Setup from flask import Flask, render_template, request, redirect, url_for app = Flask(__name__) # Simple in-memory storage posts = [] Routes @app.route('/') def index(): return render_template('index.html', posts=posts) @app.route('/post', methods=['GET', 'POST']) def create_post(): if request.method == 'POST': title = request.form['title'] content = request.form['content'] posts.append({'title': title, 'content': content}) return redirect(url_for('index')) return render_template('create_post.html') Templates <!-- index.html --> {% for post in posts %} <article> <h2>{{ post.title }}</h2> <p>{{ post.content }}</p> </article> {% endfor %} Running flask run Conclusion Build your first Flask blog application! 🚀
ReadMay 10, 2022
rust
Ownership is Rust’s unique feature that ensures memory safety without garbage collection.
Ownership Rules Each value has a single owner Only one owner at a time When owner goes out of scope, value is dropped let s = String::from("hello"); // s owns the string Moving let s1 = String::from("hello"); let s2 = s1; // s1 is moved to s2 // s1 is no longer valid Borrowing fn calculate_length(s: &String) -> usize { s.len() } let s = String::from("hello"); let len = calculate_length(&s); // Borrowing Mutable References fn change(s: &mut String) { s.push_str(", world"); } let mut s = String::from("hello"); change(&mut s); Best Practices Use references when possible Understand ownership rules Avoid unnecessary moves Use clone() sparingly Leverage the borrow checker Conclusion Master Rust ownership for memory-safe systems programming! 🦀
ReadApr 15, 2022
rust
Rust’s error handling is elegant and type-safe. Here’s how to use it effectively.
Option Type fn find_user(id: u32) -> Option<String> { if id > 0 { Some(format!("User {}", id)) } else { None } } match find_user(1) { Some(name) => println!("Found: {}", name), None => println!("Not found"), } Result Type use std::fs::File; fn read_file(path: &str) -> Result<String, std::io::Error> { std::fs::read_to_string(path) } match read_file("data.txt") { Ok(content) => println!("Content: {}", content), Err(e) => println!("Error: {}", e), } Error Propagation fn read_config() -> Result<String, std::io::Error> { let content = std::fs::read_to_string("config.txt")?; Ok(content) } Custom Errors use std::fmt; #[derive(Debug)] struct CustomError { message: String, } impl fmt::Display for CustomError { fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!(f, "{}", self.message) } } Best Practices Use Result for recoverable errors Use Option for optional values Propagate errors with ? Create custom errors when needed Handle errors explicitly Conclusion Handle errors elegantly in Rust! 🦀
ReadMar 20, 2022
python
Using SQLAlchemy with async Python requires understanding async patterns. Here’s how.
Setup from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession from sqlalchemy.orm import sessionmaker engine = create_async_engine("postgresql+asyncpg://user:pass@localhost/db") AsyncSessionLocal = sessionmaker(engine, class_=AsyncSession, expire_on_commit=False) Async Models from sqlalchemy.ext.declarative import declarative_base from sqlalchemy import Column, Integer, String Base = declarative_base() class User(Base): __tablename__ = "users" id = Column(Integer, primary_key=True) name = Column(String) Async Operations async def create_user(name: str): async with AsyncSessionLocal() as session: user = User(name=name) session.add(user) await session.commit() return user async def get_user(user_id: int): async with AsyncSessionLocal() as session: result = await session.get(User, user_id) return result Best Practices Use async context managers Commit transactions explicitly Handle exceptions properly Use connection pooling Close sessions correctly Conclusion Build efficient async database applications with SQLAlchemy! 🐍
ReadFeb 15, 2022
rust
Rust WebAssembly can significantly improve React application performance. Here’s how to integrate it.
Setup cargo install wasm-pack wasm-pack build --target web Rust Code use wasm_bindgen::prelude::*; #[wasm_bindgen] pub fn add(a: i32, b: i32) -> i32 { a + b } React Integration import init, { add } from './pkg/rust_wasm.js'; async function loadWasm() { await init(); console.log(add(2, 3)); // 5 } Performance Benefits Faster computation for heavy operations Memory efficient Type safe Near-native performance Best Practices Use for CPU-intensive tasks Minimize data transfer Profile performance Handle errors properly Bundle efficiently Conclusion Boost React performance with Rust WebAssembly! ⚡
ReadJan 20, 2022
python
Pandas provides powerful tools for joining DataFrames. Here’s a comprehensive guide.
Merge Types Inner Join import pandas as pd df1 = pd.DataFrame({'key': ['A', 'B'], 'value1': [1, 2]}) df2 = pd.DataFrame({'key': ['B', 'C'], 'value2': [3, 4]}) result = pd.merge(df1, df2, on='key', how='inner') Left Join result = pd.merge(df1, df2, on='key', how='left') Right Join result = pd.merge(df1, df2, on='key', how='right') Outer Join result = pd.merge(df1, df2, on='key', how='outer') Multiple Keys result = pd.merge(df1, df2, on=['key1', 'key2']) Best Practices Choose the right join type Handle missing values Use appropriate keys Check for duplicates Optimize for large datasets Conclusion Master Pandas joins for efficient data manipulation! 📊
ReadDec 15, 2021
python
Migrating from Python 2 to Python 3 requires careful planning. Here’s a step-by-step guide.
Key Differences Print Statement # Python 2 print "Hello" # Python 3 print("Hello") Division # Python 2 5 / 2 # 2 # Python 3 5 / 2 # 2.5 5 // 2 # 2 Unicode # Python 2 s = u"Hello" # Python 3 s = "Hello" # Unicode by default Migration Tools # 2to3 tool 2to3 -w script.py # Modernize python-modernize script.py Best Practices Test thoroughly Update dependencies Use type hints Handle bytes/strings Update string formatting Conclusion Migrate to Python 3 for modern Python development! 🐍
ReadNov 20, 2021
rust
Axum is a modern web framework for Rust. Here’s how to build your first API.
Setup [dependencies] axum = "0.7" tokio = { version = "1", features = ["full"] } serde = { version = "1.0", features = ["derive"] } Basic Server use axum::{Router, routing::get, Json}; #[tokio::main] async fn main() { let app = Router::new() .route("/", get(handler)); axum::Server::bind(&"0.0.0.0:3000".parse().unwrap()) .serve(app.into_make_service()) .await .unwrap(); } async fn handler() -> Json<serde_json::Value> { Json(serde_json::json!({"message": "Hello, World!"})) } Routes let app = Router::new() .route("/users", get(get_users)) .route("/users/:id", get(get_user)); JSON Handling use serde::{Deserialize, Serialize}; #[derive(Serialize, Deserialize)] struct User { id: u32, name: String, } async fn create_user(Json(user): Json<User>) -> Json<User> { Json(user) } Best Practices Use type-safe routing Handle errors properly Use middleware Test endpoints Document APIs Conclusion Build fast and safe APIs with Rust and Axum! 🦀
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