feat: Series.struct.dtypes

Author: chelsea-lin

bigframes/operations/structs.py

@@ -15,9 +15,11 @@
 from __future__ import annotations
 
 import bigframes_vendored.pandas.core.arrays.arrow.accessors as vendoracessors
+import pandas as pd
 
 from bigframes.core import log_adapter
 import bigframes.dataframe
+import bigframes.dtypes
 import bigframes.operations
 import bigframes.operations.base
 import bigframes.series
@@ -45,3 +47,13 @@ def explode(self) -> bigframes.dataframe.DataFrame:
  return bigframes.pandas.concat(
  [self.field(i) for i in range(pa_type.num_fields)], axis="columns"
  )
+
+ def dtypes(self) -> pd.Series:
+ pa_type = self._dtype.pyarrow_dtype
+ return pd.Series(
+ data=[
+ bigframes.dtypes.arrow_dtype_to_bigframes_dtype(pa_type.field(i).type)
+ for i in range(pa_type.num_fields)
+ ],
+ index=[pa_type.field(i).name for i in range(pa_type.num_fields)],
+ )

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

@@ -92,3 +92,32 @@ def explode(self):
  The data corresponding to all child fields.
  """
  raise NotImplementedError(constants.ABSTRACT_METHOD_ERROR_MESSAGE)
+
+ def dtypes(self):
+ """
+ Return the dtype object of each child field of the struct.
+
+ **Examples:**
+
+ >>> import bigframes.pandas as bpd
+ >>> import pyarrow as pa
+ >>> bpd.options.display.progress_bar = None
+ >>> 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.dtypes()
+ version Int64
+ project string[pyarrow]
+ dtype: object
+
+ Returns:
+ A *pandas* Series with the data type of all child fields.
+ """
+ raise NotImplementedError(constants.ABSTRACT_METHOD_ERROR_MESSAGE)