python-control · bnavigator · May 1, 2021 · Apr 29, 2021 · Apr 29, 2021 · May 1, 2021
diff --git a/control/config.py b/control/config.py
@@ -7,6 +7,8 @@
 # files.  For now, you can just choose between MATLAB and FBS default
 # values + tweak a few other things.
 
+
+import collections
 import warnings
 
 __all__ = ['defaults', 'set_defaults', 'reset_defaults',
@@ -20,7 +22,43 @@
     'control.squeeze_time_response': None,
     'forced_response.return_x': False,
 }
-defaults = dict(_control_defaults)
+
+
+class DefaultDict(collections.UserDict):
+    """Map names for settings from older version to their renamed ones.
+
+    If a user wants to write to an old setting, issue a warning and write to
+    the renamed setting instead. Accessing the old setting returns the value
+    from the new name.
+    """
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+    def __setitem__(self, key, value):
+        super().__setitem__(self._check_deprecation(key), value)
+
+    def __missing__(self, key):
+        # An old key should never have been set. If it is being accessed
+        # through __getitem__, return the value from the new name.
+        repl = self._check_deprecation(key)
+        if self.__contains__(repl):
+            return self[repl]
+        else:
+            raise KeyError(key)
+
+    def _check_deprecation(self, key):
+        if self.__contains__(f"deprecated.{key}"):
+            repl = self[f"deprecated.{key}"]
+            warnings.warn(f"config.defaults['{key}'] has been renamed to "
+                          f"config.defaults['{repl}'].",
+                          FutureWarning, stacklevel=3)
+            return repl
+        else:
+            return key
+
+
+defaults = DefaultDict(_control_defaults)
 
 
 def set_defaults(module, **keywords):

diff --git a/control/freqplot.py b/control/freqplot.py
@@ -68,8 +68,16 @@
     'freqplot.Hz': False,  # Plot frequency in Hertz
     'freqplot.grid': True,  # Turn on grid for gain and phase
     'freqplot.wrap_phase': False,  # Wrap the phase plot at a given value
+
+    # deprecations
+    'deprecated.bode.dB': 'freqplot.dB',
+    'deprecated.bode.deg': 'freqplot.deg',
+    'deprecated.bode.Hz': 'freqplot.Hz',
+    'deprecated.bode.grid': 'freqplot.grid',
+    'deprecated.bode.wrap_phase': 'freqplot.wrap_phase',
 }
 
+
 #
 # Main plotting functions
 #

diff --git a/control/tests/config_test.py b/control/tests/config_test.py
@@ -49,6 +49,49 @@ def test_get_param(self):
 
         assert ct.config._get_param('config', 'test4', {'test4': 1}, None) == 1
 
+    def test_default_deprecation(self):
+        ct.config.defaults['deprecated.config.oldkey'] = 'config.newkey'
+        ct.config.defaults['deprecated.config.oldmiss'] = 'config.newmiss'
+
+        msgpattern = r'config\.oldkey.* has been renamed to .*config\.newkey'
+
+        ct.config.defaults['config.newkey'] = 1
+        with pytest.warns(FutureWarning, match=msgpattern):
+            assert ct.config.defaults['config.oldkey'] == 1
+        with pytest.warns(FutureWarning, match=msgpattern):
+            ct.config.defaults['config.oldkey'] = 2
+        with pytest.warns(FutureWarning, match=msgpattern):
+            assert ct.config.defaults['config.oldkey'] == 2
+        assert ct.config.defaults['config.newkey'] == 2
+
+        ct.config.set_defaults('config', newkey=3)
+        with pytest.warns(FutureWarning, match=msgpattern):
+            assert ct.config._get_param('config', 'oldkey') == 3
+        with pytest.warns(FutureWarning, match=msgpattern):
+            ct.config.set_defaults('config', oldkey=4)
+        with pytest.warns(FutureWarning, match=msgpattern):
+            assert ct.config.defaults['config.oldkey'] == 4
+        assert ct.config.defaults['config.newkey'] == 4
+
+        ct.config.defaults.update({'config.newkey': 5})
+        with pytest.warns(FutureWarning, match=msgpattern):
+            ct.config.defaults.update({'config.oldkey': 6})
+        with pytest.warns(FutureWarning, match=msgpattern):
+            assert ct.config.defaults.get('config.oldkey') == 6
+
+        with pytest.raises(KeyError):
+            with pytest.warns(FutureWarning, match=msgpattern):
+                ct.config.defaults['config.oldmiss']
+        with pytest.raises(KeyError):
+            ct.config.defaults['config.neverdefined']
+
+        # assert that reset defaults keeps the custom type
+        ct.config.reset_defaults()
+        with pytest.warns(FutureWarning,
+                          match='bode.* has been renamed to.*freqplot'):
+            assert ct.config.defaults['bode.Hz'] \
+                == ct.config.defaults['freqplot.Hz']
+
     @mplcleanup
     def test_fbs_bode(self):
         ct.use_fbs_defaults()