matplotlib · tacaswell · Feb 23, 2019 · Nov 7, 2018
diff --git a/doc/api/next_api_changes/2018-11-07-removals-AL.rst b/doc/api/next_api_changes/2018-11-07-removals-AL.rst
@@ -0,0 +1,14 @@
+Removed rcParams
+````````````````
+
+The following deprecated rcParams are removed:
+
+- ``text.dvipnghack``,
+- ``nbagg.transparent`` (use :rc:`figure.facecolor` instead),
+- ``plugins.directory``,
+- ``axes.hold``,
+- ``backend.qt4`` and ``backend.qt5`` (set the :envvar:`QT_API` environment
+  variable instead).
+
+The associated validator functions ``rcsetup.validate_qt4`` and
+``validate_qt5`` are deprecated.
diff --git a/lib/matplotlib/__init__.py b/lib/matplotlib/__init__.py
@@ -612,19 +612,13 @@ def gen_candidates():
 # rcParams deprecated; some can manually be mapped to another key.
 # Values are tuples of (version, new_name_or_None).
 _deprecated_ignore_map = {
-    'text.dvipnghack': ('2.1', None),
-    'nbagg.transparent': ('2.2', 'figure.facecolor'),
-    'plugins.directory': ('2.2', None),
     'pgf.debug': ('3.0', None),
 }
 
 # rcParams deprecated; can use None to suppress warnings; remain actually
 # listed in the rcParams (not included in _all_deprecated).
 # Values are tuples of (version,)
 _deprecated_remain_as_none = {
-    'axes.hold': ('2.1',),
-    'backend.qt4': ('2.2',),
-    'backend.qt5': ('2.2',),
     'text.latex.unicode': ('3.0',),
 }
 
@@ -688,14 +682,8 @@ def __setitem__(self, key, val):
                 val = alt_val(val)
             elif key in _deprecated_remain_as_none and val is not None:
                 version, = _deprecated_remain_as_none[key]
-                addendum = ''
-                if key.startswith('backend'):
-                    addendum = (
-                        "In order to force the use of a specific Qt binding, "
-                        "either import that binding first, or set the QT_API "
-                        "environment variable.")
                 cbook.warn_deprecated(
-                    version, name=key, obj_type="rcparam", addendum=addendum)
+                    version, name=key, obj_type="rcparam")
             elif key in _deprecated_ignore_map:
                 version, alt_key = _deprecated_ignore_map[key]
                 cbook.warn_deprecated(

diff --git a/lib/matplotlib/backends/qt_compat.py b/lib/matplotlib/backends/qt_compat.py
@@ -4,11 +4,10 @@
 The selection logic is as follows:
 - if any of PyQt5, PySide2, PyQt4 or PySide have already been imported
   (checked in that order), use it;
-- otherwise, if the QT_API environment variable (used by Enthought) is
-  set, use it to determine which binding to use (but do not change the
-  backend based on it; i.e. if the Qt4Agg backend is requested but QT_API
-  is set to "pyqt5", then actually use Qt4 with the binding specified by
-  ``rcParams["backend.qt4"]``;
+- otherwise, if the QT_API environment variable (used by Enthought) is set, use
+  it to determine which binding to use (but do not change the backend based on
+  it; i.e. if the Qt5Agg backend is requested but QT_API is set to "pyqt4",
+  then actually use Qt5 with PyQt5 or PySide2 (whichever can be imported);
 - otherwise, use whatever the rcParams indicate.
 """
 
@@ -33,31 +32,25 @@
 # First, check if anything is already imported.
 if "PyQt5" in sys.modules:
     QT_API = QT_API_PYQT5
-    dict.__setitem__(rcParams, "backend.qt5", QT_API)
 elif "PySide2" in sys.modules:
     QT_API = QT_API_PYSIDE2
-    dict.__setitem__(rcParams, "backend.qt5", QT_API)
 elif "PyQt4" in sys.modules:
     QT_API = QT_API_PYQTv2
-    dict.__setitem__(rcParams, "backend.qt4", QT_API)
 elif "PySide" in sys.modules:
     QT_API = QT_API_PYSIDE
-    dict.__setitem__(rcParams, "backend.qt4", QT_API)
 # Otherwise, check the QT_API environment variable (from Enthought).  This can
 # only override the binding, not the backend (in other words, we check that the
 # requested backend actually matches).
 elif rcParams["backend"] in ["Qt5Agg", "Qt5Cairo"]:
-    if QT_API_ENV == "pyqt5":
-        dict.__setitem__(rcParams, "backend.qt5", QT_API_PYQT5)
-    elif QT_API_ENV == "pyside2":
-        dict.__setitem__(rcParams, "backend.qt5", QT_API_PYSIDE2)
-    QT_API = dict.__getitem__(rcParams, "backend.qt5")
+    if QT_API_ENV in ["pyqt5", "pyside2"]:
+        QT_API = _ETS[QT_API_ENV]
+    else:
+        QT_API = None
 elif rcParams["backend"] in ["Qt4Agg", "Qt4Cairo"]:
-    if QT_API_ENV == "pyqt4":
-        dict.__setitem__(rcParams, "backend.qt4", QT_API_PYQTv2)
-    elif QT_API_ENV == "pyside":
-        dict.__setitem__(rcParams, "backend.qt4", QT_API_PYSIDE)
-    QT_API = dict.__getitem__(rcParams, "backend.qt4")
+    if QT_API_ENV in ["pyqt4", "pyside"]:
+        QT_API = _ETS[QT_API_ENV]
+    else:
+        QT_API = None
 # A non-Qt backend was selected but we still got there (possible, e.g., when
 # fully manually embedding Matplotlib in a Qt app without using pyplot).
 else:

diff --git a/lib/matplotlib/rcsetup.py b/lib/matplotlib/rcsetup.py
@@ -267,12 +267,14 @@ def validate_backend(s):
     return backend
 
 
+@cbook.deprecated("3.1")
 def validate_qt4(s):
     if s is None:
         return None
     return ValidateInStrings("backend.qt4", ['PyQt4', 'PySide', 'PyQt4v2'])(s)
 
 
+@cbook.deprecated("3.1")
 def validate_qt5(s):
     if s is None:
         return None
@@ -993,13 +995,10 @@ def _validate_linestyle(ls):
 defaultParams = {
     'backend':           [_auto_backend_sentinel, validate_backend],
     'backend_fallback':  [True, validate_bool],
-    'backend.qt4':       [None, validate_qt4],
-    'backend.qt5':       [None, validate_qt5],
     'webagg.port':       [8988, validate_int],
     'webagg.address':    ['127.0.0.1', validate_webagg_address],
     'webagg.open_in_browser': [True, validate_bool],
     'webagg.port_retries': [50, validate_int],
-    'nbagg.transparent':       [True, validate_bool],
     'toolbar':           ['toolbar2', validate_toolbar],
     'datapath':          [None, validate_path_exists],  # handled by
                                                         # _get_data_path_cached
@@ -1129,7 +1128,6 @@ def _validate_linestyle(ls):
     'text.latex.unicode':  [True, validate_bool],
     'text.latex.preamble': ['', _validate_tex_preamble],
     'text.latex.preview':  [False, validate_bool],
-    'text.dvipnghack':     [None, validate_bool_maybe_none],
     'text.hinting':        ['auto', validate_hinting],
     'text.hinting_factor': [8, validate_int],
     'text.antialiased':    [True, validate_bool],
@@ -1415,8 +1413,6 @@ def _validate_linestyle(ls):
 
     # set this when you want to generate hardcopy docstring
     'docstring.hardcopy': [False, validate_bool],
-    # where plugin directory is locate
-    'plugins.directory':  ['.matplotlib_plugins', validate_string],
 
     'path.simplify': [True, validate_bool],
     'path.simplify_threshold': [1.0 / 9.0, ValidateInterval(0.0, 1.0)],

diff --git a/lib/matplotlib/tests/test_rcparams.py b/lib/matplotlib/tests/test_rcparams.py
@@ -124,7 +124,6 @@ def test_Bug_2543():
             _copy = mpl.rcParams.copy()
             for key in _copy:
                 mpl.rcParams[key] = _copy[key]
-            mpl.rcParams['text.dvipnghack'] = None
         with mpl.rc_context():
             _deep_copy = copy.deepcopy(mpl.rcParams)
         # real test is that this does not raise