运行next()时无法捕捉StopIteration如何解决？

Question

环境：Windows10下的python3.8.1

运行如下代码：

while True:
  for n in playerlis:
    try:
      players[str(n)].append(next(self.gencards))
    except StopIteration:
      print('finish')
      break

期望无输出，实际输出如下：

Traceback (most recent call last):
  File "F:\card.py", line 88, in __init__
    self.players[str(n)].append(next(self.gencards))
StopIteration

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<pyshell#0>", line 1, in <module>
    a = onplayobj([1,2,3])
  File "F:\card.py", line 90, in __init__
    print('finish')
KeyboardInterrupt

Answer 1

for 循环底层自动帮你捕捉 StopIteration 异常并处理了,

• For 循环被称为迭代器循环，in后跟的必须是可迭代对象

• For 循环会执行 in 后面可迭代对象的 __iter__ 方法, 拿到迭代器对象

• 然后调用迭代器对象的 __next__ 方法，拿到一个返回值赋值给 n，执行一次循环体

• 周而复始, 直到取值完毕, For 循环会检测异常自动结束循环