diff --git a/pandas/tseries/offsets.py b/pandas/tseries/offsets.py
index 0620f2b9aae49..9c0bceb1d5110 100644
--- a/pandas/tseries/offsets.py
+++ b/pandas/tseries/offsets.py
@@ -309,9 +309,8 @@ def apply_index(self, i):
 
         if type(self) is not DateOffset:
             raise NotImplementedError(
-                "DateOffset subclass {name} "
-                "does not have a vectorized "
-                "implementation".format(name=self.__class__.__name__)
+                f"DateOffset subclass {type(self).__name__} "
+                "does not have a vectorized implementation"
             )
         kwds = self.kwds
         relativedelta_fast = {
@@ -402,7 +401,7 @@ def rollback(self, dt):
         """
         dt = as_timestamp(dt)
         if not self.onOffset(dt):
-            dt = dt - self.__class__(1, normalize=self.normalize, **self.kwds)
+            dt = dt - type(self)(1, normalize=self.normalize, **self.kwds)
         return dt
 
     def rollforward(self, dt):
@@ -416,7 +415,7 @@ def rollforward(self, dt):
         """
         dt = as_timestamp(dt)
         if not self.onOffset(dt):
-            dt = dt + self.__class__(1, normalize=self.normalize, **self.kwds)
+            dt = dt + type(self)(1, normalize=self.normalize, **self.kwds)
         return dt
 
     def onOffset(self, dt):
diff --git a/pandas/util/_depr_module.py b/pandas/util/_depr_module.py
index 45e7db9281837..ae3c6359d20e0 100644
--- a/pandas/util/_depr_module.py
+++ b/pandas/util/_depr_module.py
@@ -32,7 +32,7 @@ def __init__(self, deprmod, deprmodto=None, removals=None, moved=None):
         self.moved = moved
 
         # For introspection purposes.
-        self.self_dir = frozenset(dir(self.__class__))
+        self.self_dir = frozenset(dir(type(self)))
 
     def __dir__(self):
         deprmodule = self._import_deprmod()
diff --git a/pandas/util/testing.py b/pandas/util/testing.py
index bcd12eba1651a..9adbf4cee5d74 100644
--- a/pandas/util/testing.py
+++ b/pandas/util/testing.py
@@ -713,7 +713,7 @@ def repr_class(x):
             return x
 
         try:
-            return x.__class__.__name__
+            return type(x).__name__
         except AttributeError:
             return repr(type(x))
 
@@ -780,17 +780,17 @@ def assert_is_valid_plot_return_object(objs):
     if isinstance(objs, (pd.Series, np.ndarray)):
         for el in objs.ravel():
             msg = (
-                "one of 'objs' is not a matplotlib Axes instance, type "
-                "encountered {name!r}"
-            ).format(name=el.__class__.__name__)
+                "one of 'objs' is not a matplotlib Axes instance, "
+                f"type encountered {repr(type(el).__name__)}"
+            )
             assert isinstance(el, (plt.Axes, dict)), msg
     else:
-        assert isinstance(objs, (plt.Artist, tuple, dict)), (
-            "objs is neither an ndarray of Artist instances nor a "
-            'single Artist instance, tuple, or dict, "objs" is a {name!r}'.format(
-                name=objs.__class__.__name__
-            )
+        msg = (
+            "objs is neither an ndarray of Artist instances nor a single "
+            "ArtistArtist instance, tuple, or dict, 'objs' is a "
+            f"{repr(type(objs).__name__)}"
         )
+        assert isinstance(objs, (plt.Artist, tuple, dict)), msg
 
 
 def isiterable(obj):