pkgutil.get_importer only return the first valid path_hook(importer)

GitHub fields:

assignee = None
closed_at = None
created_at = <Date 2019-03-28.00:11:08.664>
labels = ['3.7', '3.8', 'type-bug', 'library', '3.9']
title = 'pkgutil.get_importer only return the first valid path_hook(importer)'
updated_at = <Date 2020-05-05.11:54:37.129>
user = 'https://github.com/Windsooon'

bugs.python.org fields:

activity = <Date 2020-05-05.11:54:37.129>
actor = 'christian.heimes'
assignee = 'none'
closed = False
closed_date = None
closer = None
components = ['Library (Lib)']
creation = <Date 2019-03-28.00:11:08.664>
creator = 'Windson Yang'
dependencies = []
files = []
hgrepos = []
issue_num = 36453
keywords = ['patch']
message_count = 3.0
messages = ['339000', '339057', '365141']
nosy_count = 2.0
nosy_names = ['christian.heimes', 'Windson Yang']
pr_nums = ['19921']
priority = 'normal'
resolution = None
stage = 'patch review'
status = 'open'
superseder = None
type = 'behavior'
url = 'https://bugs.python.org/issue36453'
versions = ['Python 3.7', 'Python 3.8', 'Python 3.9']