'function' object is not an iterator [duplicate]

Question

def generator():
    yield 1
    yield 2
    yield 3
    yield 4
    
print(next(generator))
print(next(generator))
print(next(generator))
print(next(generator))

the error on vs is print(next(generator)) TypeError: 'function' object is not an iterator

i think the output should be 1 2 3 4

so why this error happend ?

Answer 1

you defined 'generator' as a function that returns a generator you can call next on

def get_generator()
    yield 1
    yield 2

generator = get_generator()
first_value = next(generator)
print(first_value)

Answer 2

Tru it with

generated = generator()
print(generated)
print(next(generated))

You need to call the method to start iterating it’s results

Answer 3

This is the correct version:

def generator():
    yield 1
    yield 2
    yield 3
    yield 4

iterator = generator()

print(next(iterator))
print(next(iterator))
print(next(iterator))
print(next(iterator))

A function that contains yield statements is a generator. next, however, expects a generator iterator.

Generators create generator iterators.

For more information, look here for the difference between generators and generator iterators: https://docs.python.org/3/glossary.html#term-generator