handle opitonal import

Author: shuoweil

bigframes/dataframe.py

@@ -780,9 +780,14 @@ def _repr_html_(self) -> str:
             try:
                 from bigframes import display
 
-                return display.TableWidget(self)
-            except AttributeError:
+                # Store the widget for _repr_mimebundle_ to use
+                self._anywidget_instance = display.TableWidget(self)
+                # Return a fallback HTML string
+                return "Interactive table widget (anywidget mode)"
+            except (AttributeError, ValueError):
                 # Fallback if anywidget is not available
+                import warnings
+
                 warnings.warn(
                     "Anywidget mode is not available, falling back to deferred mode."
                 )

bigframes/display/__init__.py

@@ -14,14 +14,11 @@
 
 from __future__ import annotations
 
-import warnings
-
 try:
     import anywidget  # noqa
 
     from bigframes.display.anywidget import TableWidget
 
     __all__ = ["TableWidget"]
 except Exception:
-    msg = "Anywidget mode not available as anywidget is not installed."
-    warnings.warn(msg)
+    pass

bigframes/display/anywidget.py

@@ -12,41 +12,45 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from __future__ import annotations
+
 from importlib import resources
 import functools
 import math
-from typing import Iterator
+from typing import Iterator, TYPE_CHECKING
 import uuid
 
-import anywidget  # type: ignore
 import pandas as pd
-import traitlets
 
 import bigframes
 
+# Follow the same pattern as Polars
+anywidget_installed = True
+if TYPE_CHECKING:
+    import anywidget
+    import traitlets
+else:
+    try:
+        import anywidget
+        import traitlets
+    except Exception:
+        anywidget_installed = False
+
 
 class TableWidget(anywidget.AnyWidget):
     """
     An interactive, paginated table widget for BigFrames DataFrames.
     """
 
-    @functools.cached_property
-    def _esm(self):
-        """Load JavaScript code from external file."""
-        return resources.read_text(bigframes.display, "table_widget.js")
-
-    page = traitlets.Int(0).tag(sync=True)
-    page_size = traitlets.Int(25).tag(sync=True)
-    row_count = traitlets.Int(0).tag(sync=True)
-    table_html = traitlets.Unicode().tag(sync=True)
-
     def __init__(self, dataframe):
         """
         Initialize the TableWidget.
-
         Args:
             dataframe: The Bigframes Dataframe to display.
         """
+        if not anywidget_installed:
+            raise ValueError("Anywidget is not installed, cannot create TableWidget.")
+
         super().__init__()
         self._dataframe = dataframe
 
@@ -67,6 +71,17 @@ def __init__(self, dataframe):
         # get the initial page
         self._set_table_html()
 
+    # Use functools.cached_property instead of @property for _esm
+    @functools.cached_property
+    def _esm(self):
+        """Load JavaScript code from external file."""
+        return resources.read_text(bigframes.display, "table_widget.js")
+
+    page = traitlets.Int(0).tag(sync=True)
+    page_size = traitlets.Int(25).tag(sync=True)
+    row_count = traitlets.Int(0).tag(sync=True)
+    table_html = traitlets.Unicode().tag(sync=True)
+
     @traitlets.validate("page")
     def _validate_page(self, proposal):
         """Validate and clamp page number to valid range."""
@@ -79,7 +94,6 @@ def _validate_page(self, proposal):
     def _get_next_batch(self) -> bool:
         """
         Gets the next batch of data from the generator and appends to cache.
-
         Returns:
             bool: True if a batch was successfully loaded, False otherwise.
         """
@@ -115,7 +129,7 @@ def _set_table_html(self):
         while len(self._cached_data) < end and not self._all_data_loaded:
             self._get_next_batch()
 
-        # Get the data fro the current page
+        # Get the data for the current page
         page_data = self._cached_data.iloc[start:end]
 
         # Generate HTML table
@@ -129,5 +143,5 @@ def _set_table_html(self):
 
     @traitlets.observe("page")
     def _page_changed(self, change):
-        """Handler for when the page nubmer is changed from the frontend."""
+        """Handler for when the page number is changed from the frontend."""
         self._set_table_html()

setup.py

@@ -89,6 +89,7 @@
     # install anywidget for SQL
     "anywidget": [
         "anywidget>=0.9.18",
+        "traitlets",
     ],
 }
 extras["all"] = list(sorted(frozenset(itertools.chain.from_iterable(extras.values()))))

tests/system/small/test_anywidget.py

@@ -16,7 +16,6 @@
 import pytest
 
 import bigframes as bf
-from bigframes.display import TableWidget
 
 pytest.importorskip("anywidget")
 
@@ -52,13 +51,15 @@ def paginated_bf_df(
 
 
 @pytest.fixture(scope="module")
-def table_widget(paginated_bf_df: bf.dataframe.DataFrame) -> TableWidget:
+def table_widget(paginated_bf_df: bf.dataframe.DataFrame):
     """
     Helper fixture to create a TableWidget instance with a fixed page size.
     This reduces duplication across tests that use the same widget configuration.
     """
+    from bigframes import display
+
     with bf.option_context("display.repr_mode", "anywidget", "display.max_rows", 2):
-        widget = TableWidget(paginated_bf_df)
+        widget = display.TableWidget(paginated_bf_df)
     return widget
 
 
@@ -89,9 +90,9 @@ def test_repr_anywidget_initialization_sets_page_to_zero(
 ):
     """A TableWidget should initialize with the page number set to 0."""
     with bf.option_context("display.repr_mode", "anywidget"):
-        from bigframes.display import TableWidget
+        from bigframes import display
 
-        widget = TableWidget(paginated_bf_df)
+        widget = display.TableWidget(paginated_bf_df)
 
         assert widget.page == 0
 
@@ -101,9 +102,9 @@ def test_repr_anywidget_initialization_sets_page_size_from_options(
 ):
     """A TableWidget should initialize its page size from bf.options."""
     with bf.option_context("display.repr_mode", "anywidget"):
-        from bigframes.display import TableWidget
+        from bigframes import display
 
-        widget = TableWidget(paginated_bf_df)
+        widget = display.TableWidget(paginated_bf_df)
 
         assert widget.page_size == bf.options.display.max_rows
 
@@ -114,15 +115,15 @@ def test_repr_anywidget_initialization_sets_row_count(
 ):
     """A TableWidget should initialize with the correct total row count."""
     with bf.option_context("display.repr_mode", "anywidget"):
-        from bigframes.display import TableWidget
+        from bigframes import display
 
-        widget = TableWidget(paginated_bf_df)
+        widget = display.TableWidget(paginated_bf_df)
 
         assert widget.row_count == len(paginated_pandas_df)
 
 
 def test_repr_anywidget_display_first_page_on_load(
-    table_widget: TableWidget, paginated_pandas_df: pd.DataFrame
+    table_widget, paginated_pandas_df: pd.DataFrame
 ):
     """
     Given a widget, when it is first loaded, then it should display
@@ -136,7 +137,7 @@ def test_repr_anywidget_display_first_page_on_load(
 
 
 def test_repr_anywidget_navigate_to_second_page(
-    table_widget: TableWidget, paginated_pandas_df: pd.DataFrame
+    table_widget, paginated_pandas_df: pd.DataFrame
 ):
     """
     Given a widget, when the page is set to 1, then it should display
@@ -152,7 +153,7 @@ def test_repr_anywidget_navigate_to_second_page(
 
 
 def test_repr_anywidget_navigate_to_last_page(
-    table_widget: TableWidget, paginated_pandas_df: pd.DataFrame
+    table_widget, paginated_pandas_df: pd.DataFrame
 ):
     """
     Given a widget, when the page is set to the last page (2),
@@ -168,7 +169,7 @@ def test_repr_anywidget_navigate_to_last_page(
 
 
 def test_repr_anywidget_page_clamp_to_zero_for_negative_input(
-    table_widget: TableWidget, paginated_pandas_df: pd.DataFrame
+    table_widget, paginated_pandas_df: pd.DataFrame
 ):
     """
     Given a widget, when a negative page number is set,
@@ -184,7 +185,7 @@ def test_repr_anywidget_page_clamp_to_zero_for_negative_input(
 
 
 def test_repr_anywidget_page_clamp_to_last_page_for_out_of_bounds_input(
-    table_widget: TableWidget, paginated_pandas_df: pd.DataFrame
+    table_widget, paginated_pandas_df: pd.DataFrame
 ):
     """
     Given a widget, when a page number greater than the max is set,