What is the difference between an iterator and a generator in Python?

An iterator is an object that implements the iteration protocol (iter() and next()). It allows sequential traversal of a collection's elements. A generator is a special type of iterator created using a generator function (contains the keyword yield). Generators generate values "on the fly," saving memory.

Key differences:

• Implementation: An iterator implements the iteration protocol with classes. A generator is implemented with a function containing yield.
• Memory: Generators are more memory-efficient as they generate values on demand without storing the entire sequence in memory at once. Iterators can store the entire collection.
• Single use: Generators can be used for iteration only once. An iterator, if it is not a generator, can be iterated multiple times if recreated.

# Example of an iterator
class MyIterator:
    def __init__(self, limit):
        self.limit = limit
        self.current = 0

    def __iter__(self):
        return self

    def __next__(self):
        if self.current < self.limit:
            self.current += 1
            return self.current
        else:
            raise StopIteration

# Example of a generator
def my_generator(limit):
    for i in range(1, limit + 1):
        yield i