How can you make a generator function?

A generator function in Python is created by including at least one yield statement in its body. Unlike a regular function that uses return to send a value back to the caller and then terminates, a generator function can yield multiple values, pausing its execution and allowing it to resume later. This behavior is essential for producing sequences of values over time, rather than generating and returning all at once, thus enabling memory-efficient handling of large datasets.

When the function is called, it doesn’t execute the code immediately. Instead, it returns a generator object which can be iterated over. Each time the generator is called (for example, using a loop), it runs up to the next yield statement, returns the yielded value, and suspends the function's state until the next value is requested.

In contrast, including a return statement would not suffice to create a generator, as it would terminate the function's execution and not allow multiple values to be yielded over time. Similarly, defining a function with the async keyword establishes an asynchronous function rather than a generator. Lastly, while you could technically use the generator constructor, it is not a common or necessary method for creating generators, as using yield is the default and most straightforward approach.