improvement: print matplotlib Figures/Axes in rich table output (#6904)

Fixes #6893

Print matplotlib Figures/Axes in rich table output. Updated
`narwhals_table.py` to handle of Pillow images and Matplotlib figures


<img width="1038" height="894" alt="image"
src="https://github.com/user-attachments/assets/d261b09b-4aee-4ecf-b135-c04bfcefaadb"
/>

---------

Co-authored-by: Shahmir Varqha <[email protected]>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: 3 people

marimo/_plugins/ui/_impl/tables/narwhals_table.py

@@ -715,9 +715,37 @@ def _sanitize_table_value(self, value: Any) -> Any:
 
         # Handle Pillow images
         if DependencyManager.pillow.imported():
-            from PIL import Image
+            try:
+                from PIL import Image
+
+                if isinstance(value, Image.Image):
+                    return io_to_data_url(value, "image/png")
+            except Exception:
+                LOGGER.debug(
+                    "Unable to convert image to data URL", exc_info=True
+                )
 
-            if isinstance(value, Image.Image):
-                return io_to_data_url(value, "image/png")
+        # Handle Matplotlib figures
+        if DependencyManager.matplotlib.imported():
+            try:
+                import matplotlib.figure
+                from matplotlib.axes import Axes
+
+                from marimo._output.formatting import as_html
+                from marimo._plugins.stateless.flex import vstack
+
+                if isinstance(value, matplotlib.figure.Figure):
+                    html = as_html(vstack([str(value), value]))
+                    mimetype, data = html._mime_()
+
+                if isinstance(value, Axes):
+                    html = as_html(vstack([str(value), value]))
+                    mimetype, data = html._mime_()
+                    return {"mimetype": mimetype, "data": data}
+            except Exception:
+                LOGGER.debug(
+                    "Error converting matplotlib figures to HTML",
+                    exc_info=True,
+                )
 
         return value

marimo/_smoke_tests/pandas/pandas_subplots.py

@@ -0,0 +1,122 @@
+# /// script
+# requires-python = ">=3.11"
+# dependencies = [
+#     "pandas",
+#     "matplotlib",
+# ]
+# ///
+
+import marimo
+
+__generated_with = "0.17.0"
+app = marimo.App(width="medium")
+
+
+@app.cell
+def _():
+    import marimo as mo
+    return (mo,)
+
+
+@app.cell(hide_code=True)
+def _(mo):
+    mo.md(
+        """
+    # Issue #6893: Pandas Subplots Not Displaying
+
+    This smoke test reproduces the issue where pandas DataFrame box plots
+    with `subplots=True` don't render properly in marimo.
+
+    **Expected behavior**: Box plots should display as images
+
+    **Actual behavior**: Only textual representation appears
+
+    The issue occurs because `df.plot.box(subplots=True)` returns a numpy
+    ndarray of matplotlib Axes objects, which marimo doesn't currently format.
+    """
+    )
+    return
+
+
+@app.cell
+def _():
+    import pandas as pd
+    import matplotlib
+
+    # Load NYC taxi data from stable GitHub URL
+    taxi_url = (
+        "https://raw.githubusercontent.com/mwaskom/seaborn-data/master/taxis.csv"
+    )
+    df = pd.read_csv(taxi_url)
+    df
+    return (df,)
+
+
+@app.cell(hide_code=True)
+def _(mo):
+    mo.md("""## Test Case 1: Box plot WITHOUT subplots (works correctly)""")
+    return
+
+
+@app.cell
+def _(df):
+    # This should work - returns a single Axes object
+    df[["distance", "total"]].plot.box()
+    return
+
+
+@app.cell(hide_code=True)
+def _(mo):
+    mo.md(
+        """
+    ## Test Case 2: Box plot WITH subplots (reproduces issue #6893)
+
+    This is the exact scenario from the bug report.
+    """
+    )
+    return
+
+
+@app.cell
+def _(df):
+    # This reproduces the issue - returns ndarray of Axes
+    df[["distance", "total"]].plot.box(subplots=True)
+    return
+
+
+@app.cell(hide_code=True)
+def _(mo):
+    mo.md("""## Test Case 3: Multiple subplots with custom layout""")
+    return
+
+
+@app.cell
+def _(df):
+    # Test with 2x2 layout - also returns ndarray of Axes
+    df[["distance", "total", "fare", "tip"]].plot.box(
+        subplots=True, layout=(2, 2), figsize=(10, 8)
+    )
+    return
+
+
+@app.cell(hide_code=True)
+def _(mo):
+    mo.md(
+        """
+    ## Test Case 4: 1D array of subplots
+
+    Test with a single row of subplots.
+    """
+    )
+    return
+
+
+@app.cell
+def _(df):
+    # Returns 1D ndarray of Axes
+    df[["fare", "tip", "tolls"]].plot.box(subplots=True, layout=(1, 3))
+    return
+
+
+if __name__ == "__main__":
+    app.run()

marimo/_smoke_tests/sql/numpy_sql.py

@@ -0,0 +1,43 @@
+import marimo
+
+__generated_with = "0.17.0"
+app = marimo.App(width="medium", sql_output="native")
+
+
+@app.cell
+def _():
+    import marimo as mo
+    import pandas as pd
+    import numpy as np
+    import sqlglot
+    import pyarrow
+    return np, pd
+
+
+@app.cell
+def _(np, pd):
+    example_df = pd.DataFrame(
+        [
+            [np.random.random(size=[2, 2]) for _col in range(2)]
+            for _row in range(3)
+        ],
+        columns=["A", "B"],
+    )
+    return (example_df,)
+
+
+@app.cell
+def _(example_df):
+    import duckdb
+
+    res = duckdb.sql(
+        f"""
+        SELECT COUNT(*) FROM example_df
+        """,
+    )
+    print(res)
+    return
+
+
+if __name__ == "__main__":
+    app.run()

tests/_plugins/ui/_impl/tables/test_narwhals.py

@@ -1600,3 +1600,117 @@ def test_calculate_top_k_rows_cache_invalidation(df: Any) -> None:
 
     # Verify the actual results are different
     assert result1 != result2
+
+
+@pytest.mark.skipif(not HAS_DEPS, reason="optional dependencies not installed")
+class TestSanitizeTableValue:
+    """Tests for the _sanitize_table_value method."""
+
+    def setUp(self) -> None:
+        import polars as pl
+
+        self.data = pl.DataFrame({"A": [1, 2, 3]})
+        self.manager = NarwhalsTableManager.from_dataframe(self.data)
+
+    def test_sanitize_none(self) -> None:
+        """Test that None values are returned as-is."""
+        manager = self._get_manager()
+        assert manager._sanitize_table_value(None) is None
+
+    def test_sanitize_primitive_values(self) -> None:
+        """Test that primitive values are returned unchanged."""
+        manager = self._get_manager()
+        assert manager._sanitize_table_value(42) == 42
+        assert manager._sanitize_table_value("hello") == "hello"
+        assert manager._sanitize_table_value(3.14) == 3.14
+        assert manager._sanitize_table_value(True) is True
+
+    @pytest.mark.skipif(
+        not DependencyManager.pillow.has(),
+        reason="Pillow not installed",
+    )
+    def test_sanitize_pillow_image(self) -> None:
+        """Test that Pillow images are converted to data URLs."""
+        from PIL import Image
+
+        manager = self._get_manager()
+
+        # Create a simple test image
+        img = Image.new("RGB", (10, 10), color="red")
+
+        result = manager._sanitize_table_value(img)
+
+        # Verify it returns a data URL string
+        assert isinstance(result, str)
+        assert result.startswith("data:image/png;base64,")
+
+    @pytest.mark.skipif(
+        not DependencyManager.matplotlib.has(),
+        reason="Matplotlib not installed",
+    )
+    def test_sanitize_matplotlib_figure(self) -> None:
+        """Test that Matplotlib figures are returned unchanged (no conversion)."""
+        import matplotlib.pyplot as plt
+
+        manager = self._get_manager()
+
+        # Create a simple figure
+        fig, ax = plt.subplots()
+        ax.plot([1, 2, 3], [1, 2, 3])
+
+        result = manager._sanitize_table_value(fig)
+
+        # Figure is currently returned unchanged because there's no return statement for figures
+        # (only for axes)
+        assert result == fig
+
+        plt.close(fig)
+
+    @pytest.mark.skipif(
+        not DependencyManager.matplotlib.has(),
+        reason="Matplotlib not installed",
+    )
+    def test_sanitize_matplotlib_axes(self) -> None:
+        """Test that Matplotlib axes are converted to HTML."""
+        import matplotlib.pyplot as plt
+
+        manager = self._get_manager()
+
+        # Create a simple axes
+        fig, ax = plt.subplots()
+        ax.plot([1, 2, 3], [1, 2, 3])
+
+        result = manager._sanitize_table_value(ax)
+
+        # Verify it returns a dict with mimetype and data
+        assert isinstance(result, dict)
+        assert "mimetype" in result
+        assert "data" in result
+
+        plt.close(fig)
+
+    def test_sanitize_unsupported_types(self) -> None:
+        """Test that unsupported types are returned unchanged."""
+        manager = self._get_manager()
+
+        # Test various unsupported types
+        class CustomClass:
+            pass
+
+        obj = CustomClass()
+        assert manager._sanitize_table_value(obj) == obj
+
+        # Test dict
+        d = {"key": "value"}
+        assert manager._sanitize_table_value(d) == d
+
+        # Test list
+        lst = [1, 2, 3]
+        assert manager._sanitize_table_value(lst) == lst
+
+    def _get_manager(self) -> NarwhalsTableManager[Any]:
+        """Helper method to create a manager."""
+        import polars as pl
+
+        data = pl.DataFrame({"A": [1, 2, 3]})
+        return NarwhalsTableManager.from_dataframe(data)