Use partial in set_ticklabels instead of an argument in FuncFormatter.

efiring · efiring · commit 6bfbb6c87dd5 · 2020-04-30T11:13:54.000-10:00
diff --git a/lib/matplotlib/axis.py b/lib/matplotlib/axis.py
@@ -3,6 +3,7 @@
 """
 
 import datetime
+import functools
 import logging
 
 import numpy as np
@@ -1601,7 +1602,7 @@ def set_pickradius(self, pickradius):
 
     # Helper for set_ticklabels. Defining it here makes it pickleable.
     @staticmethod
-    def _format_with_dict(x, pos, tickd):
+    def _format_with_dict(tickd, x, pos):
         return tickd.get(x, "")
 
     def set_ticklabels(self, ticklabels, *, minor=False, **kwargs):
@@ -1635,7 +1636,8 @@ def set_ticklabels(self, ticklabels, *, minor=False, **kwargs):
                    else self.get_major_locator())
         if isinstance(locator, mticker.FixedLocator):
             tickd = {loc: lab for loc, lab in zip(locator.locs, ticklabels)}
-            formatter = mticker.FuncFormatter(self._format_with_dict, tickd)
+            func = functools.partial(self._format_with_dict, tickd)
+            formatter = mticker.FuncFormatter(func)
         else:
             formatter = mticker.FixedFormatter(ticklabels)
         if minor:
diff --git a/lib/matplotlib/ticker.py b/lib/matplotlib/ticker.py
@@ -379,13 +379,11 @@ class FuncFormatter(Formatter):
 
     The function should take in two inputs (a tick value ``x`` and a
     position ``pos``), and return a string containing the corresponding
-    tick label.  The function may take additional arguments that are
-    supplied upon instantiation.
+    tick label.
     """
 
-    def __init__(self, func, *args):
+    def __init__(self, func):
         self.func = func
-        self.args = args
         self.offset_string = ""
 
     def __call__(self, x, pos=None):
@@ -394,7 +392,7 @@ def __call__(self, x, pos=None):
 
         *x* and *pos* are passed through as-is.
         """
-        return self.func(x, pos, *self.args)
+        return self.func(x, pos)
 
     def get_offset(self):
         return self.offset_string
