Merge in pending changes from v0.16.x

docs/compatible_idioms.rst

@@ -512,7 +512,7 @@ Iterable dict values:
 .. code:: python
 
     # Python 2 and 3: option 2
-    from builtins import itervalues
+    from future.utils import itervalues
     # or
     from six import itervalues
 

docs/notebooks/Writing Python 2-3 compatible code.ipynb

@@ -1129,7 +1129,7 @@
    "outputs": [],
    "source": [
     "# Python 2 and 3: option 2\n",
-    "from builtins import itervalues\n",
+    "from future.utils import itervalues\n",
     "# or\n",
     "from six import itervalues\n",
     "\n",

docs/whatsnew.rst

@@ -5,7 +5,15 @@ What's New
 
 .. _whats-new-0.16.x:
 
-What's new in version 0.16.0 (2016-09-22)
+What's new in version 0.16.1 (unreleased)
+=========================================
+
+This is a minor bug-fix release:
+
+- Fix `from collections import ChainMap` after install_aliases() (issue #226)
+
+
+What's new in version 0.16.0 (2016-10-27)
 ==========================================
 
 This release removes the ``configparser`` package as an alias for
@@ -26,18 +34,18 @@ effect on your system.
 This releases also fixes these bugs:
 
 - Fix ``newbytes`` constructor bug. (Issue #163)
-- Fix semantics of `bool()` with `newobject`. (Issue #211)
-- Fix `standard_library.install_aliases()` on PyPy. (Issue #205)
-- Fix assertRaises for `pow` and `compile` on Python 3.5. (Issue #183)
-- Fix return argument of `future.utils.ensure_new_type` if conversion to
+- Fix semantics of ``bool()`` with ``newobject``. (Issue #211)
+- Fix ``standard_library.install_aliases()`` on PyPy. (Issue #205)
+- Fix assertRaises for ``pow`` and ``compile``` on Python 3.5. (Issue #183)
+- Fix return argument of ``future.utils.ensure_new_type`` if conversion to
   new type does not exist. (Issue #185)
-- Add missing `cmp_to_key` for Py2.6. (Issue #189)
-- Allow the `old_div` fixer to be disabled. (Issue #190)
+- Add missing ``cmp_to_key`` for Py2.6. (Issue #189)
+- Allow the ``old_div`` fixer to be disabled. (Issue #190)
 - Improve compatibility with Google App Engine. (Issue #231)
-- Add some missing imports to the `tkinter` and `tkinter.filedialog`
+- Add some missing imports to the ``tkinter`` and ``tkinter.filedialog``
   package namespaces. (Issues #212 and #233)
-- Fix ``raise_from`` on PY3 when the exception cannot be recreated from
-  its repr. (Issues #213 and #235, fix provided by Varriount)
+- More complete implementation of ``raise_from`` on PY3. (Issues #141,
+  #213 and #235, fix provided by Varriount)
 
 
 What's new in version 0.15.2 (2015-09-11)

src/future/standard_library/__init__.py

@@ -180,6 +180,7 @@
 MOVES = [('collections', 'UserList', 'UserList', 'UserList'),
          ('collections', 'UserDict', 'UserDict', 'UserDict'),
          ('collections', 'UserString','UserString', 'UserString'),
+         ('collections', 'ChainMap', 'future.backports.misc', 'ChainMap'),
          ('itertools', 'filterfalse','itertools', 'ifilterfalse'),
          ('itertools', 'zip_longest','itertools', 'izip_longest'),
          ('sys', 'intern','__builtin__', 'intern'),

tests/test_future/test_chainmap.py

@@ -0,0 +1,160 @@
+"""
+Tests for the future.standard_library module
+"""
+
+from __future__ import absolute_import, print_function
+from future import standard_library
+from future import utils
+from future.tests.base import unittest, CodeHandler, expectedFailurePY2
+
+import sys
+import tempfile
+import os
+import copy
+import textwrap
+from subprocess import CalledProcessError
+
+
+class TestChainMap(CodeHandler):
+
+    def setUp(self):
+        self.interpreter = sys.executable
+        standard_library.install_aliases()
+        super(TestChainMap, self).setUp()
+
+    def tearDown(self):
+        # standard_library.remove_hooks()
+        pass
+
+    @staticmethod
+    def simple_cm():
+        from collections import ChainMap
+        c = ChainMap()
+        c['one'] = 1
+        c['two'] = 2
+
+        cc = c.new_child()
+        cc['one'] = 'one'
+
+        return c, cc
+
+
+    def test_repr(self):
+        c, cc = TestChainMap.simple_cm()
+
+        order1 = "ChainMap({'one': 'one'}, {'one': 1, 'two': 2})"
+        order2 = "ChainMap({'one': 'one'}, {'two': 2, 'one': 1})"
+        assert repr(cc) in [order1, order2]
+
+
+    def test_recursive_repr(self):
+        """
+        Test for degnerative recursive cases. Very unlikely in
+        ChainMaps. But all must bow before the god of testing coverage.
+        """
+        from collections import ChainMap
+        c = ChainMap()
+        c['one'] = c
+        assert repr(c) == "ChainMap({'one': ...})"
+
+
+    def test_get(self):
+        c, cc = TestChainMap.simple_cm()
+
+        assert cc.get('two') == 2
+        assert cc.get('three') == None
+        assert cc.get('three', 'notthree') == 'notthree'
+
+
+    def test_bool(self):
+        from collections import ChainMap
+        c = ChainMap()
+        assert not(bool(c))
+
+        c['one'] = 1
+        c['two'] = 2
+        assert bool(c)
+
+        cc = c.new_child()
+        cc['one'] = 'one'
+        assert cc
+
+
+    def test_fromkeys(self):
+        from collections import ChainMap
+        keys = 'a b c'.split()
+        c = ChainMap.fromkeys(keys)
+        assert len(c) == 3
+        assert c['a'] == None
+        assert c['b'] == None
+        assert c['c'] == None
+
+
+    def test_copy(self):
+        c, cc = TestChainMap.simple_cm()
+        new_cc = cc.copy()
+        assert new_cc is not cc
+        assert sorted(new_cc.items()) == sorted(cc.items())
+
+
+    def test_parents(self):
+        c, cc = TestChainMap.simple_cm()
+
+        new_c = cc.parents
+        assert c is not new_c
+        assert len(new_c) == 2
+        assert new_c['one'] == c['one']
+        assert new_c['two'] == c['two']
+
+
+    def test_delitem(self):
+        c, cc = TestChainMap.simple_cm()
+
+        with self.assertRaises(KeyError):
+            del cc['two']
+
+        del cc['one']
+        assert len(cc) == 2
+        assert cc['one'] == 1
+        assert cc['two'] == 2
+
+
+    def test_popitem(self):
+        c, cc = TestChainMap.simple_cm()
+
+        assert cc.popitem() == ('one', 'one')
+
+        with self.assertRaises(KeyError):
+            cc.popitem()
+
+
+    def test_pop(self):
+        c, cc = TestChainMap.simple_cm()
+
+        assert cc.pop('one') == 'one'
+
+        with self.assertRaises(KeyError):
+            cc.pop('two')
+
+        assert len(cc) == 2
+
+
+    def test_clear(self):
+        c, cc = TestChainMap.simple_cm()
+
+        cc.clear()
+        assert len(cc) == 2
+        assert cc['one'] == 1
+        assert cc['two'] == 2
+
+
+    def test_missing(self):
+
+        c, cc = TestChainMap.simple_cm()
+
+        with self.assertRaises(KeyError):
+            cc['clown']
+
+
+if __name__ == '__main__':
+    unittest.main()

tests/test_future/test_standard_library.py

@@ -247,6 +247,13 @@ def test_itertools_zip_longest(self):
         self.assertEqual(list(zip_longest(a, b)),
                          [(1, 2), (2, 4), (None, 6)])
 
+    def test_ChainMap(self):
+        """
+        Tests whether collections.ChainMap is available.
+        """
+        from collections import ChainMap
+        cm = ChainMap()
+
     @unittest.expectedFailure
     @unittest.skipIf(utils.PY3, 'generic import tests are for Py2 only')
     def test_import_failure_from_module(self):