我创建了一个服务帐户并分配了以下角色：
Owner
Storage Admin
Storage Object Admin
Tester
Tester 是我为学习目的创建的具有以下权限的角色：
storage.buckets.create
storage.buckets.delete
storage.buckets.get
storage.buckets.getIamPolicy
storage.buckets.list
storage.buckets.setIamPolicy
storage.buckets.update
storage.objects.create
storage.objects.delete
storage.objects.get
storage.objects.getIamPolicy
storage.objects.list
storage.objects.setIamPolicy
storage.objects.update
...
我知道我不必要地过度使用这些角色的权限；但是，这仅用于测试目的。
考虑到bucket只包含一个文件并且账户有相应的权限，下面的Python代码应该可以工作（在我的本地计算机上运行）：
Owner
Storage Admin
Storage Object Admin
Tester
但它没有：
Traceback (most recent call last):
File "gcloud/test.py", line 8, in <module>
for blob in blobs:
File "/home/user/.local/lib/python3.6/site-packages/google/api_core/page_iterator.py", line 212, in _items_iter
for page in self._page_iter(increment=False):
File "/home/berkay/.local/lib/python3.6/site-packages/google/api_core/page_iterator.py", line 243, in _page_iter
page = self._next_page()
File "/home/user/.local/lib/python3.6/site-packages/google/api_core/page_iterator.py", line 369, in _next_page
response = self._get_next_page_response()
File "/home/user/.local/lib/python3.6/site-packages/google/api_core/page_iterator.py", …