feat(python): add notebook html repr for Series (#5653)

py-polars/polars/_html.py

@@ -26,7 +26,7 @@ def __enter__(self) -> None:
             s = f"<{self.tag} "
             for k, v in self.attributes.items():
                 s += f'{k}="{v}" '
-            s += ">"
+            s = f"{s.rstrip()}>"
             self.elements.append(s)
         else:
             self.elements.append(f"<{self.tag}>")
@@ -46,13 +46,16 @@ def __init__(
         df: DataFrame,  # type: ignore[name-defined] # noqa: F821
         max_cols: int = 75,
         max_rows: int = 40,
+        from_series: bool = False,
     ):
         self.df = df
         self.elements: list[str] = []
         self.max_cols = max_cols
         self.max_rows = max_rows
+        self.series = from_series
         self.row_idx: Iterable[int]
         self.col_idx: Iterable[int]
+
         if max_rows < df.height:
             self.row_idx = (
                 list(range(0, max_rows // 2))
@@ -72,7 +75,11 @@ def __init__(
 
     def write_header(self) -> None:
         """Write the header of an HTML table."""
-        self.elements.append(f"<small>shape: {self.df.shape}</small>")
+        shape = self.df.shape
+        if self.series:
+            shape = shape[:1]
+
+        self.elements.append(f"<small>shape: {shape}</small>")
         with Tag(self.elements, "thead"):
             with Tag(self.elements, "tr"):
                 columns = self.df.columns
@@ -122,8 +129,7 @@ class NotebookFormatter(HTMLFormatter):
     """
     Class for formatting output data in HTML for display in Jupyter Notebooks.
 
-    This class is intended for functionality specific to DataFrame._repr_html_()
-    and DataFrame.to_html(notebook=True).
+    This class is intended for functionality specific to DataFrame._repr_html_().
 
     """
 

py-polars/polars/internals/dataframe/frame.py

@@ -1471,7 +1471,7 @@ def __deepcopy__(self: DF, memo: None = None) -> DF:
     def _ipython_key_completions_(self) -> list[str]:
         return self.columns
 
-    def _repr_html_(self) -> str:
+    def _repr_html_(self, **kwargs: Any) -> str:
         """
         Format output data in HTML for display in Jupyter Notebooks.
 
@@ -1489,7 +1489,15 @@ def _repr_html_(self) -> str:
         if max_rows < 0:
             max_rows = self.shape[0]
 
-        return "\n".join(NotebookFormatter(self, max_cols, max_rows).render())
+        from_series = kwargs.get("from_series", False)
+        return "\n".join(
+            NotebookFormatter(
+                self,
+                max_cols=max_cols,
+                max_rows=max_rows,
+                from_series=from_series,
+            ).render()
+        )
 
     def to_arrow(self) -> pa.Table:
         """

py-polars/polars/internals/series/series.py

@@ -950,6 +950,10 @@ def __array_ufunc__(
                 f" `{method}`."
             )
 
+    def _repr_html_(self) -> str:
+        """Format output data in HTML for display in Jupyter Notebooks."""
+        return self.to_frame()._repr_html_(from_series=True)
+
     def estimated_size(self, unit: SizeUnit = "b") -> int | float:
         """
         Return an estimation of the total (heap) allocated size of the Series.

py-polars/tests/unit/test_df.py

@@ -1182,8 +1182,9 @@ def test_literal_series() -> None:
 
 
 def test_to_html(df: pl.DataFrame) -> None:
-    # check if it does not panic/ error
-    df._repr_html_()
+    # check it does not panic/error, and appears to contain a table
+    html = df._repr_html_()
+    assert "<table" in html
 
 
 def test_rows() -> None:

py-polars/tests/unit/test_series.py

@@ -2395,6 +2395,12 @@ class XSeries(pl.Series):
         assert str(n) in x_repr
 
 
+def test_repr_html(df: pl.DataFrame) -> None:
+    # check it does not panic/error, and appears to contain a table
+    html = pl.Series("misc", [123, 456, 789])._repr_html_()
+    assert "<table" in html
+
+
 def test_builtin_abs() -> None:
     s = pl.Series("s", [-1, 0, 1, None])
     assert abs(s).to_list() == [1, 0, 1, None]