from .abc import AbstractResolver
__all__ = ('ThreadedResolver', 'AsyncResolver', 'DefaultResolver')
try:
import aiodns
# aiodns_default = hasattr(aiodns.DNSResolver, 'gethostbyname')
except ImportError: # pragma: no cover
aiodns = None
aiodns_default = False
# ...
DefaultResolver = AsyncResolver if aiodns_default else ThreadedResolver
never use aiodns,why?
in resolver.py