在生成器函数中获取 StopIteration 错误

Question

I'm using a generator function to returns 10 ' valid ' numbers one after the other.

The check_id_valid() function returns True or False depending on whether the number is valid or not. The problem is that I'm getting a StopIteration error after producing only one valid number.

The check_id_valid() function is working well, I checked it by sending it parameters directly: print(check_id_valid(123456780)) .

The generator function:

def id_generator(Id_number):
    Id_number +=1
    valid_id = (check_id_valid(Id_number))
    while not valid_id:
        Id_number += 1
        valid_id = check_id_valid(Id_number)
        yield Id_number

def main():
    id_gen = id_generator(123456780)
    try:
        for item in range(10):
            print(next(id_gen))
    except (illigalDigits, illigalException) as e:
        print(e)

if __name__ == "__main__":
    main()

The error:

   print(next(id_gen))
StopIteration
>>>

Answer 1

Your generator function only yield s once, so needs to be changed to do so more than that. Here's a runnable example and the output it produces:

# A little scaffolding to make code runnable.
class illigalDigits(Exception): pass
class illigalException(Exception): pass

def check_id_valid(id):
    return id  # Consider anything valid.
########

def id_generator(Id_number):
    while True:
        Id_number += 1
        valid_id = check_id_valid(Id_number)
        if valid_id:
            yield Id_number

def main():
    id_gen = id_generator(123456780)
    try:
        for _ in range(10):
            print(next(id_gen))
    except (illigalDigits, illigalException) as e:
        print(e)

if __name__ == "__main__":
    main()

Output:

123456781
123456782
123456783
123456784
123456785
123456786
123456787
123456788
123456789
123456790