FibGenerator.py

from collections.abc import Iterable, Iterator

def Fib(max):
    n, a, b = 0, 0, 1
    while n < max:
        yield b
        a, b = b, a + b
        n = n + 1
    return 'done'


f = Fib(10000)

print(isinstance(f, Iterator))
print(next(f))
print(next(f))
print(next(f))
print(next(f))

# True
# 1
# 1
# 2
# 3