问题描述
我要发送的数字大于999999999时，我想引发stopiteration异常。
当我直接向print(check_id_valid(1234567980))函数参数或IDIterator类（迭代器class）发送参数，并从那里将数字传递给check_id_valid()函数时，捕获到异常放在main()上。
错误字符串将被打印：
Reached max number,1234567980 is over 9 digits
但是当我将数字发送到id_generator()函数时（感谢先前的帮助，该函数正常工作），
stopiteration不会引发main()异常
def check_id_valid(id_number):
if len(str(id_number)) < 9:
raise illigalException(id_number)
if int(id_number) > 999999999:
raise stopiteration(id_number)
def id_generator(Id_number):
while True:
Id_number += 1
if check_id_valid(Id_number):
yield Id_number
def main():
id_gen = id_generator(1234567800)
try:
for item in range(10):
print(next(id_gen))
except stopiteration as e:
print("Reached max number," + str(e) + " is over 9 digits")
except (illigalException) as e:
print(e)
if __name__ == "__main__":
main()
错误消息是-
raise stopiteration(id_number) stopiteration: 1234567801 The above exception was the direct cause of the following exception:
print(next(id_gen)) RuntimeError: generator raised stopiteration
我该如何解决？
PS
我需要使用内置的stopiteration异常，而不是覆盖它。
解决方法
Python生成器返回时将自动引发StopIteration。因此，您不应该自己在生成器函数中引发StopIteration。
StopIteration在迭代器中用于停止迭代，例如在for循环内。
def check_id_valid(id_number):
if len(str(id_number)) < 9:
raise illigalException(id_number)
if int(id_number) > 999999999:
return False
# you need to return True if is valid.
return True
def id_generator(Id_number):
while True:
Id_number += 1
if check_id_valid(Id_number):
yield Id_number
else:
# this return here will raise the StopIteration error with message id_number for you.
return id_number
更新
# assuming your check_id_valid is still the same.
def id_generator(Id_number):
while True:
Id_number += 1
try:
check_id_valid(Id_number)
except StopIteration:
# this return will raise StopIteration when you call next() on id_generator
return Id_number
except Exception as e:
# raise the other illigalException
raise e
yield Id_number