關於yield和yield from

一.簡單示例

def yield_func():
    for  _ in range(2):
        yield "12"


def yield_from_func():
    for  _ in range(2):
        yield from '12'
        
for a in yield_func():
    print(a)

for a in yield_from_func():
    print(a)
    
 '''
12
12
1
2
1
2
'''   
很明顯就能看出來yield from就是把迭代器再進行一次迭代器生成能夠想象成[12,12]變成[1,2,1,2]把裏面第一次迭代後的每一個值再進行一次迭代