diff --git a/pint/delegates/formatter/base_formatter.py b/pint/delegates/formatter/base_formatter.py
index d618b2140..f0db6c5ff 100644
--- a/pint/delegates/formatter/base_formatter.py
+++ b/pint/delegates/formatter/base_formatter.py
@@ -35,7 +35,16 @@
 
 class BaseFormatter:
     # This default order for sorting dimensions was described in the proposed ISO 80000 specification.
-    dim_order = ( "[substance]", "[mass]", "[current]", "[luminosity]", "[length]", "[]", "[time]", "[temperature]", )
+    dim_order = (
+        "[substance]",
+        "[mass]",
+        "[current]",
+        "[luminosity]",
+        "[length]",
+        "[]",
+        "[time]",
+        "[temperature]",
+    )
 
     def format_quantity(
         self, quantity: PlainQuantity[MagnitudeT], spec: str = ""
diff --git a/pint/facets/plain/definitions.py b/pint/facets/plain/definitions.py
index c32637e75..44bf29858 100644
--- a/pint/facets/plain/definitions.py
+++ b/pint/facets/plain/definitions.py
@@ -11,7 +11,6 @@
 import itertools
 import numbers
 import typing as ty
-import ast
 from dataclasses import dataclass
 from functools import cached_property
 from typing import Any, Optional