Checking for length of categories before doing string conversion. fixes pandas-dev#11305

Author: michaelaye

pandas/core/categorical.py

@@ -1389,12 +1389,13 @@ def _repr_categories(self):
         max_categories = (10 if get_option("display.max_categories") == 0
                     else get_option("display.max_categories"))
         from pandas.core import format as fmt
-        category_strs = fmt.format_array(self.categories, None)
-        if len(category_strs) > max_categories:
+        if len(self.categories) > max_categories:
             num = max_categories // 2
-            head = category_strs[:num]
-            tail = category_strs[-(max_categories - num):]
+            head = fmt.format_array(self.categories[:num], None)
+            tail = fmt.format_array(self.categories[-num:], None)
             category_strs = head + ["..."] + tail
+        else:
+            category_strs = fmt.format_array(self.categories, None)
 
         # Strip all leading spaces, which format_array adds for columns...
         category_strs = [x.strip() for x in category_strs]