Minor changes

Author: topper-123

pandas/core/arrays/categorical.py

@@ -2691,4 +2691,4 @@ def _factorize_from_iterables(iterables):
     if len(iterables) == 0:
         # For consistency, it should return a list of 2 lists.
         return [[], []]
-    return map(list, zip(*[_factorize_from_iterable(it) for it in iterables]))
+    return map(list, zip(*(_factorize_from_iterable(it) for it in iterables)))

pandas/core/generic.py

@@ -6502,7 +6502,7 @@ def replace(self, to_replace=None, value=None, inplace=False, limit=None,
                 regex = True
 
             items = list(to_replace.items())
-            keys, values = zip(*items) if len(items) else ([], [])
+            keys, values = zip(*items) if items else ([], [])
 
             are_mappings = [is_dict_like(v) for v in values]
 

pandas/io/parsers.py

@@ -1488,7 +1488,7 @@ def _extract_multi_indexer_columns(self, header, index_names, col_names,
         def extract(r):
             return tuple(r[i] for i in range(field_count) if i not in sic)
 
-        columns = list(zip(*[extract(r) for r in header]))
+        columns = list(zip(*(extract(r) for r in header)))
         names = ic + columns
 
         # If we find unnamed columns all in a single