implement explode

bigframes/dataframe.py

@@ -161,7 +161,15 @@ def __init__(
                 columns=columns,  # type:ignore
                 dtype=dtype,  # type:ignore
             )
-            if pd_dataframe.size < MAX_INLINE_DF_SIZE:
+            if (
+                pd_dataframe.size < MAX_INLINE_DF_SIZE
+                # TODO(swast): Workaround data types limitation in inline data.
+                and not any(
+                    dt.pyarrow_dtype
+                    for dt in pd_dataframe.dtypes
+                    if isinstance(dt, pandas.ArrowDtype)
+                )
+            ):
                 self._block = blocks.block_from_local(
                     pd_dataframe, session or bigframes.pandas.get_global_session()
                 )

bigframes/operations/base.py

@@ -86,7 +86,15 @@ def __init__(
             if pd_series.name is None:
                 # to_frame will set default numeric column label if unnamed, but we do not support int column label, so must rename
                 pd_dataframe = pd_dataframe.set_axis(["unnamed_col"], axis=1)
-            if pd_dataframe.size < MAX_INLINE_SERIES_SIZE:
+            if (
+                pd_dataframe.size < MAX_INLINE_SERIES_SIZE
+                # TODO(swast): Workaround data types limitation in inline data.
+                and not any(
+                    dt.pyarrow_dtype
+                    for dt in pd_dataframe.dtypes
+                    if isinstance(dt, pd.ArrowDtype)
+                )
+            ):
                 self._block = blocks.block_from_local(
                     pd_dataframe, session or bigframes.pandas.get_global_session()
                 )

bigframes/operations/structs.py

@@ -35,7 +35,7 @@ def _as_ibis(self, x: ibis_types.Value):
             name = self._name_or_index
         else:
             name = struct_value.names[self._name_or_index]
-        return struct_value[name]
+        return struct_value[name].name(name)
 
 
 class StructAccessor(
@@ -44,4 +44,18 @@ class StructAccessor(
     __doc__ = vendoracessors.StructAccessor.__doc__
 
     def field(self, name_or_index: str | int) -> bigframes.series.Series:
-        return self._apply_unary_op(StructField(name_or_index))
+        series = self._apply_unary_op(StructField(name_or_index))
+        if isinstance(name_or_index, str):
+            name = name_or_index
+        else:
+            struct_field = self._dtype.pyarrow_dtype[name_or_index]
+            name = struct_field.name
+        return series.rename(name)
+
+    def explode(self) -> bigframes.dataframe.DataFrame:
+        import bigframes.pandas
+
+        pa_type = self._dtype.pyarrow_dtype
+        return bigframes.pandas.concat(
+            [self.field(i) for i in range(pa_type.num_fields)], axis="columns"
+        )

bigframes/series.py

@@ -51,6 +51,7 @@
 import bigframes.operations.base
 import bigframes.operations.datetimes as dt
 import bigframes.operations.strings as strings
+import bigframes.operations.structs as structs
 import third_party.bigframes_vendored.pandas.core.series as vendored_pandas_series
 
 LevelType = typing.Union[str, int]
@@ -118,6 +119,10 @@ def query_job(self) -> Optional[bigquery.QueryJob]:
             self._set_internal_query_job(self._compute_dry_run())
         return self._query_job
 
+    @property
+    def struct(self) -> structs.StructAccessor:
+        return structs.StructAccessor(self._block)
+
     def _set_internal_query_job(self, query_job: bigquery.QueryJob):
         self._query_job = query_job
 

third_party/bigframes_vendored/pandas/core/arrays/arrow/accessors.py

@@ -61,3 +61,39 @@ def field(self, name_or_index: str | int):
         Name: version, dtype: int64[pyarrow]
         """
         raise NotImplementedError(constants.ABSTRACT_METHOD_ERROR_MESSAGE)
+
+    def explode(self):
+        """
+        Extract all child fields of a struct as a DataFrame.
+
+        Returns
+        -------
+        pandas.DataFrame
+            The data corresponding to all child fields.
+
+        See Also
+        --------
+        Series.struct.field : Return a single child field as a Series.
+
+        Examples
+        --------
+        >>> import bigframes.pandas as bpd
+        >>> import pyarrow as pa
+        >>> s = bpd.Series(
+        ...     [
+        ...         {"version": 1, "project": "pandas"},
+        ...         {"version": 2, "project": "pandas"},
+        ...         {"version": 1, "project": "numpy"},
+        ...     ],
+        ...     dtype=bpd.ArrowDtype(pa.struct(
+        ...         [("version", pa.int64()), ("project", pa.string())]
+        ...     ))
+        ... )
+
+        >>> s.struct.explode()
+           version project
+        0        1  pandas
+        1        2  pandas
+        2        1   numpy
+        """
+        raise NotImplementedError(constants.ABSTRACT_METHOD_ERROR_MESSAGE)