enumerate() and zip() — stop writing index-juggling loops

Reaching for range(len(items)) is usually a sign that enumerate() or zip() would read better and break less.

enumerate(): index + value together

When you need the position and the item, ask for both:

for i, name in enumerate(names, start=1):
    print(f"{i}. {name}")

zip(): walk two sequences at once

Pairing elements by position is what zip() is for. It stops at the shortest input, so you never index out of range:

for product, price in zip(products, prices):
    print(product, price)

Combine them

They compose cleanly — enumerate(zip(a, b)) gives you an index alongside each pair. Prefer these over manual counters; the intent is obvious and there is nothing to keep in sync.