What is the difference between a data processing cycle mechanism and a structure for sequential traversal?

The cyclic data processing mechanism (for example, a cyclic iterator) allows you to endlessly traverse a data set, repeating elements in a circle. This is useful when you need to continuously iterate over elements without stopping.

A structure for sequential traversal (for example, a regular iterator or list) provides a one-time pass through the elements, from start to finish, after which the iteration ends.

Example in Python:

from itertools import cycle

items = [1, 2, 3]

# Sequential traversal
for item in items:
    print(item)  # 1, 2, 3

# Cyclic traversal
cycler = cycle(items)
for _ in range(6):
    print(next(cycler))  # 1, 2, 3, 1, 2, 3

Thus, the main difference is that the cyclic mechanism repeats elements infinitely, while the sequential one does so only once.