CLN: clean indexes/multi.py (pandas-dev#29337)

Author: topper-123

pandas/core/indexes/multi.py

@@ -704,22 +704,23 @@ def _set_levels(
         # This is NOT part of the levels property because it should be
         # externally not allowed to set levels. User beware if you change
         # _levels directly
-        if validate and len(levels) == 0:
-            raise ValueError("Must set non-zero number of levels.")
-        if validate and level is None and len(levels) != self.nlevels:
-            raise ValueError("Length of levels must match number of levels.")
-        if validate and level is not None and len(levels) != len(level):
-            raise ValueError("Length of levels must match length of level.")
+        if validate:
+            if len(levels) == 0:
+                raise ValueError("Must set non-zero number of levels.")
+            if level is None and len(levels) != self.nlevels:
+                raise ValueError("Length of levels must match number of levels.")
+            if level is not None and len(levels) != len(level):
+                raise ValueError("Length of levels must match length of level.")
 
         if level is None:
             new_levels = FrozenList(
                 ensure_index(lev, copy=copy)._shallow_copy() for lev in levels
             )
         else:
-            level = [self._get_level_number(l) for l in level]
+            level_numbers = [self._get_level_number(lev) for lev in level]
             new_levels = list(self._levels)
-            for l, v in zip(level, levels):
-                new_levels[l] = ensure_index(v, copy=copy)._shallow_copy()
+            for lev_num, lev in zip(level_numbers, levels):
+                new_levels[lev_num] = ensure_index(lev, copy=copy)._shallow_copy()
             new_levels = FrozenList(new_levels)
 
         if verify_integrity:
@@ -825,22 +826,23 @@ def labels(self):
     def _set_codes(
         self, codes, level=None, copy=False, validate=True, verify_integrity=False
     ):
-        if validate and level is None and len(codes) != self.nlevels:
-            raise ValueError("Length of codes must match number of levels")
-        if validate and level is not None and len(codes) != len(level):
-            raise ValueError("Length of codes must match length of levels.")
+        if validate:
+            if level is None and len(codes) != self.nlevels:
+                raise ValueError("Length of codes must match number of levels")
+            if level is not None and len(codes) != len(level):
+                raise ValueError("Length of codes must match length of levels.")
 
         if level is None:
             new_codes = FrozenList(
                 _ensure_frozen(level_codes, lev, copy=copy)._shallow_copy()
                 for lev, level_codes in zip(self._levels, codes)
             )
         else:
-            level = [self._get_level_number(l) for l in level]
+            level_numbers = [self._get_level_number(lev) for lev in level]
             new_codes = list(self._codes)
-            for lev_idx, level_codes in zip(level, codes):
-                lev = self.levels[lev_idx]
-                new_codes[lev_idx] = _ensure_frozen(
+            for lev_num, level_codes in zip(level_numbers, codes):
+                lev = self.levels[lev_num]
+                new_codes[lev_num] = _ensure_frozen(
                     level_codes, lev, copy=copy
                 )._shallow_copy()
             new_codes = FrozenList(new_codes)
@@ -1253,17 +1255,18 @@ def _set_names(self, names, level=None, validate=True):
             raise ValueError("Names should be list-like for a MultiIndex")
         names = list(names)
 
-        if validate and level is not None and len(names) != len(level):
-            raise ValueError("Length of names must match length of level.")
-        if validate and level is None and len(names) != self.nlevels:
-            raise ValueError(
-                "Length of names must match number of levels in MultiIndex."
-            )
+        if validate:
+            if level is not None and len(names) != len(level):
+                raise ValueError("Length of names must match length of level.")
+            if level is None and len(names) != self.nlevels:
+                raise ValueError(
+                    "Length of names must match number of levels in MultiIndex."
+                )
 
         if level is None:
             level = range(self.nlevels)
         else:
-            level = [self._get_level_number(l) for l in level]
+            level = [self._get_level_number(lev) for lev in level]
 
         # set the name
         for lev, name in zip(level, names):