diff --git a/Lib/collections/__init__.py b/Lib/collections/__init__.py
index 59a2d520fe..f7348ee918 100644
--- a/Lib/collections/__init__.py
+++ b/Lib/collections/__init__.py
@@ -45,6 +45,11 @@ except ImportError:
 else:
     _collections_abc.MutableSequence.register(deque)
 
+try:
+    from _collections import _deque_iterator
+except ImportError:
+    pass
+
 try:
     from _collections import defaultdict
 except ImportError:
@@ -94,17 +99,19 @@ class OrderedDict(dict):
     # Individual links are kept alive by the hard reference in self.__map.
     # Those hard references disappear when a key is deleted from an OrderedDict.
 
+    def __new__(cls, /, *args, **kwds):
+        "Create the ordered dict object and set up the underlying structures."
+        self = dict.__new__(cls)
+        self.__hardroot = _Link()
+        self.__root = root = _proxy(self.__hardroot)
+        root.prev = root.next = root
+        self.__map = {}
+        return self
+
     def __init__(self, other=(), /, **kwds):
         '''Initialize an ordered dictionary.  The signature is the same as
         regular dictionaries.  Keyword argument order is preserved.
         '''
-        try:
-            self.__root
-        except AttributeError:
-            self.__hardroot = _Link()
-            self.__root = root = _proxy(self.__hardroot)
-            root.prev = root.next = root
-            self.__map = {}
         self.__update(other, **kwds)
 
     def __setitem__(self, key, value,
@@ -271,7 +278,7 @@ class OrderedDict(dict):
         'od.__repr__() <==> repr(od)'
         if not self:
             return '%s()' % (self.__class__.__name__,)
-        return '%s(%r)' % (self.__class__.__name__, list(self.items()))
+        return '%s(%r)' % (self.__class__.__name__, dict(self.items()))
 
     def __reduce__(self):
         'Return state information for pickling'
@@ -511,9 +518,12 @@ def namedtuple(typename, field_names, *, rename=False, defaults=None, module=Non
     # specified a particular module.
     if module is None:
         try:
-            module = _sys._getframe(1).f_globals.get('__name__', '__main__')
-        except (AttributeError, ValueError):
-            pass
+            module = _sys._getframemodulename(1) or '__main__'
+        except AttributeError:
+            try:
+                module = _sys._getframe(1).f_globals.get('__name__', '__main__')
+            except (AttributeError, ValueError):
+                pass
     if module is not None:
         result.__module__ = module
 
@@ -1015,8 +1025,8 @@ class ChainMap(_collections_abc.MutableMapping):
 
     def __iter__(self):
         d = {}
-        for mapping in reversed(self.maps):
-            d.update(dict.fromkeys(mapping))    # reuses stored hash values if possible
+        for mapping in map(dict.fromkeys, reversed(self.maps)):
+            d |= mapping                        # reuses stored hash values if possible
         return iter(d)
 
     def __contains__(self, key):
@@ -1136,10 +1146,17 @@ class UserDict(_collections_abc.MutableMapping):
     def __iter__(self):
         return iter(self.data)
 
-    # Modify __contains__ to work correctly when __missing__ is present
+    # Modify __contains__ and get() to work like dict
+    # does when __missing__ is present.
     def __contains__(self, key):
         return key in self.data
 
+    def get(self, key, default=None):
+        if key in self:
+            return self[key]
+        return default
+
+
     # Now, add the methods in dicts but not in MutableMapping
     def __repr__(self):
         return repr(self.data)