matplotlib · jklymak · Mar 28, 2018 · Mar 27, 2018
diff --git a/doc/api/next_api_changes/2018-02-26-AL-removals.rst b/doc/api/next_api_changes/2018-02-26-AL-removals.rst
@@ -26,8 +26,12 @@ The following deprecated API elements have been removed:
 - ``_AxesBase.axesPatch``, ``_AxesBase.get_cursor_props``,
   ``_AxesBase.set_cursor_props``,
 - ``_ImageBase.iterpnames``,
+- ``FigureCanvasBase.start_event_loop_default``;
+- ``FigureCanvasBase.stop_event_loop_default``;
 - ``Figure.figurePatch``,
 - ``FigureCanvasBase.dynamic_update``, ``FigureCanvasBase.idle_event``,
   ``FigureCanvasBase.get_linestyle``, ``FigureCanvasBase.set_linestyle``,
 - ``FigureCanvasQTAgg.blitbox``,
+- passing non-numbers to ``EngFormatter.format_eng``,
 - passing ``frac`` to ``PolarAxes.set_theta_grids``,
+- any mention of idle events,
diff --git a/lib/matplotlib/backend_bases.py b/lib/matplotlib/backend_bases.py
@@ -2337,13 +2337,7 @@ def on_press(event):
                 print('you pressed', event.button, event.xdata, event.ydata)
 
             cid = canvas.mpl_connect('button_press_event', on_press)
-
         """
-        if s == 'idle_event':
-            cbook.warn_deprecated(1.5,
-                "idle_event is only implemented for the wx backend, and will "
-                "be removed in matplotlib 2.1. Use the animations module "
-                "instead.")
 
         return self.callbacks.connect(s, func)
 
@@ -2428,11 +2422,6 @@ def stop_event_loop(self):
         """
         self._looping = False
 
-    start_event_loop_default = cbook.deprecated(
-        "2.1", name="start_event_loop_default")(start_event_loop)
-    stop_event_loop_default = cbook.deprecated(
-        "2.1", name="stop_event_loop_default")(stop_event_loop)
-
 
 def key_press_handler(event, canvas, toolbar=None):
     """

diff --git a/lib/matplotlib/ticker.py b/lib/matplotlib/ticker.py
@@ -1253,43 +1253,31 @@ def format_eng(self, num):
         '1.0 M'
 
         >>> format_eng("-1e-6") # for self.places = 2
-        u'-1.00 \N{GREEK SMALL LETTER MU}'
-
-        `num` may be a numeric value or a string that can be converted
-        to a numeric value with ``float(num)``.
+        '-1.00 \N{GREEK SMALL LETTER MU}'
         """
-        if isinstance(num, six.string_types):
-            warnings.warn(
-                "Passing a string as *num* argument is deprecated since"
-                "Matplotlib 2.1, and is expected to be removed in 2.3.",
-                mplDeprecation)
-
-        dnum = float(num)
         sign = 1
         fmt = "g" if self.places is None else ".{:d}f".format(self.places)
 
-        if dnum < 0:
+        if num < 0:
             sign = -1
-            dnum = -dnum
+            num = -num
 
-        if dnum != 0:
-            pow10 = int(math.floor(math.log10(dnum) / 3) * 3)
+        if num != 0:
+            pow10 = int(math.floor(math.log10(num) / 3) * 3)
         else:
             pow10 = 0
-            # Force dnum to zero, to avoid inconsistencies like
+            # Force num to zero, to avoid inconsistencies like
             # format_eng(-0) = "0" and format_eng(0.0) = "0"
             # but format_eng(-0.0) = "-0.0"
-            dnum = 0.0
+            num = 0.0
 
         pow10 = np.clip(pow10, min(self.ENG_PREFIXES), max(self.ENG_PREFIXES))
 
-        mant = sign * dnum / (10.0 ** pow10)
-        # Taking care of the cases like 999.9..., which
-        # may be rounded to 1000 instead of 1 k.  Beware
-        # of the corner case of values that are beyond
+        mant = sign * num / (10.0 ** pow10)
+        # Taking care of the cases like 999.9..., which may be rounded to 1000
+        # instead of 1 k.  Beware of the corner case of values that are beyond
         # the range of SI prefixes (i.e. > 'Y').
-        _fmant = float("{mant:{fmt}}".format(mant=mant, fmt=fmt))
-        if _fmant >= 1000 and pow10 != max(self.ENG_PREFIXES):
+        if float(format(mant, fmt)) >= 1000 and pow10 < max(self.ENG_PREFIXES):
             mant /= 1000
             pow10 += 3