Bug multiple css selectors GH44011

doc/source/whatsnew/v1.4.0.rst

@@ -544,6 +544,7 @@ Styler
 - Bug when rendering an empty DataFrame with a named index (:issue:`43305`).
 - Bug when rendering a single level MultiIndex (:issue:`43383`).
 - Bug when combining non-sparse rendering and :meth:`.Styler.hide_columns` or :meth:`.Styler.hide_index` (:issue:`43464`)
+- Bug in :class:`.Styler`  when setting a table style for a specified column using set_table_styles, the column was only applied to the final selector tag if they are named in a comma seperated list (:issue:`44011`)
 
 Other
 ^^^^^

pandas/io/formats/style.py

@@ -53,6 +53,7 @@
     StylerRenderer,
     Subset,
     Tooltips,
+    format_table_styles,
     maybe_convert_css_to_tuples,
     non_reducing_slice,
     refactor_levels,
@@ -2047,7 +2048,7 @@ def set_table_styles(
                 }
                 for key, styles in table_styles.items()
                 for idx in obj.get_indexer_for([key])
-                for s in styles
+                for s in format_table_styles(styles)
             ]
         else:
             table_styles = [

pandas/io/formats/style_render.py

@@ -226,7 +226,7 @@ def _translate(
         # construct render dict
         d = {
             "uuid": self.uuid,
-            "table_styles": _format_table_styles(self.table_styles or []),
+            "table_styles": format_table_styles(self.table_styles or []),
             "caption": self.caption,
         }
 
@@ -1173,7 +1173,7 @@ def _is_visible(idx_row, idx_col, lengths) -> bool:
     return (idx_col, idx_row) in lengths
 
 
-def _format_table_styles(styles: CSSStyles) -> CSSStyles:
+def format_table_styles(styles: CSSStyles) -> CSSStyles:
     """
     looks for multiple CSS selectors and separates them:
     [{'selector': 'td, th', 'props': 'a:v;'}]

pandas/tests/io/formats/style/test_style.py

@@ -829,6 +829,17 @@ def test_table_styles_multiple(self):
             {"selector": "tr", "props": [("color", "green")]},
         ]
 
+    def test_table_styles_multiple_borders(self):
+        # GH 4411
+        style_table_setting = self.df.style.set_table_styles(
+            [{"selector": "th,td", "props": [("border-left", "2px solid black")]}]
+        )._translate(True, True)["tables_styles"]
+
+        assert style_table_setting == [
+            {"selector": "th", "props": [("border-left", "2px solid black")]},
+            {"selector": "td", "props": [("border-left", "2px solid black")]},
+        ]
+
     def test_maybe_convert_css_to_tuples(self):
         expected = [("a", "b"), ("c", "d e")]
         assert maybe_convert_css_to_tuples("a:b;c:d e;") == expected