MAINT: Tweak for slightly better readability (#3451)

Author: j-t-1

pypdf/generic/_data_structures.py

@@ -92,6 +92,7 @@
     from typing_extensions import Self
 
 logger = logging.getLogger(__name__)
+
 IndirectPattern = re.compile(rb"[+-]?(\d+)\s+(\d+)\s+R[^a-zA-Z]")
 
 
@@ -210,8 +211,8 @@ def __isub__(self, lst: Any) -> Self:
         """Allow to remove items"""
         for x in self._to_lst(lst):
             try:
-                x = self.index(x)
-                del self[x]
+                index = self.index(x)
+                del self[index]
             except ValueError:
                 pass
         return self
@@ -318,11 +319,11 @@ def _clone(
             ignore_fields:
 
         """
-        # first we remove for the ignore_fields
+        # First we remove the ignore_fields
         # that are for a limited number of levels
-        x = 0
         assert ignore_fields is not None
         ignore_fields = list(ignore_fields)
+        x = 0
         while x < len(ignore_fields):
             if isinstance(ignore_fields[x], int):
                 if cast(int, ignore_fields[x]) <= 0:
@@ -331,7 +332,7 @@ def _clone(
                     continue
                 ignore_fields[x] -= 1  # type:ignore
             x += 1
-        #  First check if this is a chain list, we need to loop to prevent recur
+        #  Check if this is a chain list, we need to loop to prevent recur
         if any(
             field not in ignore_fields
             and field in src
@@ -354,8 +355,8 @@ def _clone(
                         and k not in self
                         and isinstance(src.raw_get(k), IndirectObject)
                         and isinstance(src[k], DictionaryObject)
-                        # IF need to go further the idea is to check
-                        # that the types are the same:
+                        # If need to go further the idea is to check
+                        # that the types are the same
                         and (
                             src.get("/Type", None) is None
                             or cast(DictionaryObject, src[k]).get("/Type", None) is None
@@ -374,7 +375,7 @@ def _clone(
                                     cur_obj.__class__(), pdf_dest, force_duplicate
                                 ),
                             )
-                            # check to see if we've previously processed our item
+                            # Check to see if we've previously processed our item
                             if clon.indirect_reference is not None:
                                 idnum = clon.indirect_reference.idnum
                                 generation = clon.indirect_reference.generation