Python Iterators
Python iterators are objects that implement the iterator protocol, allowing sequential access to elements in a collection or data stream. They define a __next__() method to return the next item and raise StopIteration when exhausted, and are created from iterables using the iter() function. This concept is fundamental for efficient, memory-friendly looping and data processing in Python.
Developers should learn Python iterators to write memory-efficient code when handling large datasets or streams, as they enable lazy evaluation by processing items one at a time instead of loading everything into memory. They are essential for custom data structures, generator functions, and integration with built-in tools like for loops, comprehensions, and functions such as map() and filter().