Fix collections.abc imports for python 3.7.

Author: hwms

hyper/common/headers.py

@@ -5,12 +5,16 @@
 
 Contains hyper's structures for storing and working with HTTP headers.
 """
-import collections
+try:
+    from collections.abc import MutableMapping
+except ImportError:  # pragma: no cover
+    # Python 2.7 compatibility
+    from collections import MutableMapping
 
 from hyper.common.util import to_bytestring, to_bytestring_tuple
 
 
-class HTTPHeaderMap(collections.MutableMapping):
+class HTTPHeaderMap(MutableMapping):
     """
     A structure that contains HTTP headers.
 

hyper/http11/connection.py

@@ -10,9 +10,12 @@
 import socket
 import base64
 
-from collections import Iterable, Mapping
+try:
+    from collections.abc import Iterable, Mapping
+except ImportError:  # pragma: no cover
+    # Python 2.7 compatibility
+    from collections import Iterable, Mapping
 
-import collections
 from hyperframe.frame import SettingsFrame
 
 from .response import HTTP11Response
@@ -390,7 +393,7 @@ def _send_body(self, body, body_type):
                 return
 
             # Iterables that set a specific content length.
-            elif isinstance(body, collections.Iterable):
+            elif isinstance(body, Iterable):
                 for item in body:
                     try:
                         self._sock.send(item)