Output formatting: preserve quoting for string categories

Author: jorisvandenbossche

pandas/core/arrays/categorical.py

@@ -2233,8 +2233,14 @@ def _repr_categories(self) -> list[str]:
         )
         from pandas.io.formats import format as fmt
 
+        formatter = None
+        if self.categories.dtype == "str":
+            # the extension array formatter defaults to boxed=True in format_array
+            # override here to boxed=False to be consistent with QUOTE_NONNUMERIC
+            formatter = self.categories._values._formatter(boxed=False)
+
         format_array = partial(
-            fmt.format_array, formatter=None, quoting=QUOTE_NONNUMERIC
+            fmt.format_array, formatter=formatter, quoting=QUOTE_NONNUMERIC
         )
         if len(self.categories) > max_categories:
             num = max_categories // 2