Flask code explainers

python

import os
from datetime import timedelta

Class-based config in a Flask app factory

configuration app-factory inheritance

Intermediate 7 steps

python

import time
 
from flask import Flask, g, request

Timing requests with Flask hooks

middleware request-lifecycle instrumentation

Intermediate 5 steps

python

from decimal import Decimal, ROUND_HALF_UP
 
from babel.numbers import format_currency
from flask import Flask

Building a currency Jinja filter in Flask

template filters decimal precision internationalization

Intermediate 6 steps

python

from functools import wraps
 
import jwt
from flask import current_app, g, jsonify, request

How a JWT auth decorator works in Flask

decorators authentication jwt

Intermediate 6 steps

python

from flask import Blueprint, jsonify, request, abort
from flask_caching import Cache
 
cache = Cache(config={"CACHE_TYPE": "RedisCache", "CACHE_REDIS_URL": "redis://localhost:6379/0"})

Custom cache keys for Flask endpoints

caching redis cache-invalidation

Intermediate 7 steps

python

from flask import Flask, g, jsonify, request, abort
from sqlalchemy import create_engine
from sqlalchemy.orm import scoped_session, sessionmaker

Per-request SQLAlchemy sessions in Flask

database sessions request lifecycle connection management

Intermediate 7 steps

python

from functools import wraps
from flask import Blueprint, session, request, redirect, url_for, flash, render_template
from werkzeug.security import check_password_hash

Session-based auth with a Flask Blueprint

authentication decorators sessions

Intermediate 9 steps

python

import os
import uuid
 
from flask import Blueprint, current_app, jsonify, request

Handling secure file uploads in Flask

file-upload validation blueprints

Intermediate 8 steps

python

import logging
import traceback
 
from flask import Blueprint, jsonify, request

Centralized JSON error handling in Flask

error-handling blueprints json-api

Intermediate 5 steps

python

from datetime import datetime, date
from decimal import Decimal
from flask import Flask, jsonify
from flask.json.provider import DefaultJSONProvider

Serializing SQLAlchemy models in Flask JSON

serialization orm json

Intermediate 6 steps

python

from flask import Blueprint, jsonify, request, abort
 
from .models import Article, db
from .schemas import article_schema, articles_schema

Building a REST articles API with Flask Blueprints

rest-api blueprints serialization

Intermediate 7 steps

python

import csv
import io
from datetime import datetime

Streaming a CSV export in Flask

streaming generators csv

Intermediate 9 steps

python

import time
from collections import defaultdict
from threading import Lock

Sliding-window login rate limiting in Flask

rate-limiting sliding-window thread-safety

Intermediate 7 steps

python

from flask import Blueprint, render_template, redirect, url_for, flash
from flask_login import login_required, current_user
from flask_wtf import FlaskForm
from wtforms import StringField, TextAreaField, SubmitField

Handling a post form with a Flask Blueprint

blueprints form-validation post-redirect-get

Intermediate 7 steps

python

import hashlib
import hmac
import os

Verifying signed payment webhooks in Flask

hmac webhooks signature verification

Intermediate 7 steps

python

from flask import Blueprint, render_template, request, abort
from sqlalchemy import select
 
from .models import Article

Paginating articles in a Flask Blueprint

pagination blueprints input-validation

Intermediate 6 steps