问题分析

调用了很多接口，使用域名访问的就会报此错误，使用IP直接访问的就没问题。所以怀疑是域名处理部分有问题，并且域名中有大写字母，更加重怀疑是某云的API网关区分host大小写导致。

解决问题

咱是对接方，只能咱们改。

项目中最后都会调用requests库进行最终的http调用，因此我们跟踪源码调试，发现有几个地方会讲url转换为小写。

1. requests/packages/urllib3/poolmanager.py文件

   
   def _default_key_normalizer(key_class, request_context):
       """
       Create a pool key of type ``key_class`` for a request.
   	...
       """
       context = {}
       for key in key_class._fields:
           context[key] = request_context.get(key)
       context['scheme'] = context['scheme'].lower()
       # 将此处转小写删掉
       #context['host'] = context['host'].lower()
       return key_class(**context)
   

2. requests/packages/urllib3/util/url.py文件

   class Url(namedtuple('Url', url_attrs)):
       """
       Datastructure for representing an HTTP URL. Used as a return value for
       :func:`parse_url`. Both the scheme and host are normalized as they are
       both case-insensitive according to RFC 3986.
       """
       __slots__ = ()
   
       def __new__(cls, scheme=None, auth=None, host=None, port=None, path=None,
                   query=None, fragment=None):
           if path and not path.startswith('/'):
               path = '/' + path
           if scheme:
               scheme = scheme.lower()
           # 将此处转小写删掉
           #if host:
           #    host = host.lower()
           return super(Url, cls).__new__(cls, scheme, auth, host, port, path,
                                          query, fragment)
   

3. requests/models.py文件

   class PreparedRequest(RequestEncodingMixin, RequestHooksMixin):
       ...
       def prepare_url(self, url, params):
        	...
           try:
           	# 将uts46参数改为False
               #host = idna.encode(host, uts46=True).decode('utf-8')
               host = idna.encode(host, uts46=False).decode('utf-8')
           except (UnicodeError, idna.IDNAError):
               if not unicode_is_ascii(host) or host.startswith(u'*'):
                   raise InvalidURL('URL has an invalid label.')  
           ...