diff --git a/pandas/errors/__init__.py b/pandas/errors/__init__.py
index 43ce8ad4abb45..ebe9a3d5bf472 100644
--- a/pandas/errors/__init__.py
+++ b/pandas/errors/__init__.py
@@ -156,19 +156,23 @@ class MergeError(ValueError):
 
 
 class AccessorRegistrationWarning(Warning):
-    """Warning for attribute conflicts in accessor registration."""
+    """
+    Warning for attribute conflicts in accessor registration.
+    """
 
 
 class AbstractMethodError(NotImplementedError):
-    """Raise this error instead of NotImplementedError for abstract methods
+    """
+    Raise this error instead of NotImplementedError for abstract methods
     while keeping compatibility with Python 2 and Python 3.
     """
 
     def __init__(self, class_instance, methodtype="method"):
         types = {"method", "classmethod", "staticmethod", "property"}
         if methodtype not in types:
-            msg = f"methodtype must be one of {methodtype}, got {types} instead."
-            raise ValueError(msg)
+            raise ValueError(
+                f"methodtype must be one of {methodtype}, got {types} instead."
+            )
         self.methodtype = methodtype
         self.class_instance = class_instance
 
@@ -177,5 +181,4 @@ def __str__(self) -> str:
             name = self.class_instance.__name__
         else:
             name = type(self.class_instance).__name__
-        msg = f"This {self.methodtype} must be defined in the concrete class {name}"
-        return msg.format(methodtype=self.methodtype, name=name)
+        return f"This {self.methodtype} must be defined in the concrete class {name}"