Quickstart: Cut bandwidth with conditional requests

Send the ETag back

etag = cache.get('products_etag')
headers = {'If-None-Match': etag} if etag else {}
r = requests.get(f'{BASE}/products', headers=headers, timeout=10)
if r.status_code == 304:
    return cache.get('products')          # unchanged
r.raise_for_status()
cache.set('products_etag', r.headers.get('ETag'))
cache.set('products', r.json()['data'])

When it helps

Conditional requests shine when you poll reference data that rarely changes. You still make the request, but a 304 skips the body, saving bandwidth and parsing on every unchanged poll.