def fib(num):
  a, b, c = 1, 0, 1　　　　
  while a <= num:
    yield c
    b, c = c, b + c
    a += 1
for n in fib(10):
  print(n, end=' ')
# 1 1 2 3 5 8 13 21 34 55

from collections import Iterable, Iterator
print(isinstance(fib(10), Iterable))
print(isinstance(range(10), Iterable))
# True
# True

from collections import Iterator
print(isinstance(list(), Iterator))
# False

print(isinstance(iter(list()), Iterator))
# True