Flask-Limiter

import os
from flask import Flask
from flask_limiter import Limiter
from flask_limiter.util import get_remote_address

app = Flask(__name__)

# Configure storage_uri, using in-memory for example, or from an environment variable
# In-memory storage is for development/testing only and should not be used in production with multiple workers.
# For production, use backends like Redis: 'redis://localhost:6379'
storage_uri = os.environ.get('FLASK_RATELIMIT_STORAGE_URI', 'memory://')

limiter = Limiter(
    key_func=get_remote_address,
    app=app,
    default_limits=["200 per day", "50 per hour"],
    storage_uri=storage_uri,
    strategy="fixed-window" # Or 'moving-window', 'sliding-window-counter'
)

@app.route("/slow")
@limiter.limit("1 per day")
def slow():
    return ":("

@app.route("/medium")
@limiter.limit("1/second", override_defaults=False)
def medium():
    return ":|"

@app.route("/fast")
def fast():
    return ":)"

@app.route("/ping")
@limiter.exempt
def ping():
    return "PONG"

# Example error handler for rate limit exceeded (HTTP 429)
@app.errorhandler(429)
def ratelimit_handler(e):
    return f"Rate limit exceeded: {e.description}", 429

if __name__ == '__main__':
    app.run(debug=True)