ZhouYang1993

my_list = [1, 2, 3, 4, 5]
print(my_list)
# [1, 2, 3, 4, 5]

my_list_iterator = iter(my_list)
print(my_list_iterator)
# <list_iterator object at 0x7f048a4b67f0>

next(my_list_iterator)
# 1

ZhouYang1993

from collections.abc import Iterable, Iterator

my_list = [1, 2, 3, 4, 5]
my_list_iterator = iter(my_list)

isinstance(my_list,Iterable)
# True
isinstance(my_list,Iterator)
# False
isinstance(my_list_iterator,Iterable)

ZhouYang1993

from collections.abc import Iterable, Iterator
my_list = [1, 2, 3, 4, 5]
my_list_iterator = iter(my_list)

isinstance(my_list,Iterable)
#True
isinstance(my_list,Iterator)
#False
isinstance(my_list_iterator,Iterable)
#True

ZhouYang1993

from collections.abc import Iterable, Iterator

class Fib(object):
    def __init__(self):
        self.a, self.b = 0, 1

    def __iter__(self):
        return self

    def __next__(self):

ZhouYang1993

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'

ZhouYang1993

# convert an Iterable to an Iterator
my_list_iterator = iter(my_list)

while True:
    try:
        # get the next item
        element = next(my_list_iterator)
    except StopIteration:
        # if StopIteration is raised, stop for loop
        break

ZhouYang1993

my_list = [i for i in range(8)]
my_generator = (i for i in range(8))

print(my_list)
print(my_generator)

# [0, 1, 2, 3, 4, 5, 6, 7]
# <generator object <genexpr> at 0x7f8fc3ec9a40>

ZhouYang1993

def my_generator(maximum):
    n = 0
    while n < maximum:
        n += 1
        yield n
    return 'Done'


g = my_generator(maximum=5)

ZhouYang1993

def my_generator(maximum):
    n = 0
    while n < maximum:
        yield n
    return 'Done'

print(type(my_generator))
# <class 'function'>
print(type(my_generator(5)))
# <class 'generator'>

ZhouYang1993

def example():
    print('step 1')
    yield 1
    print('step 2')
    yield 2
    print('step 3')
    yield 3
    
g = example()