fix!: Address the series input type issue in bigframes functions

bigframes/functions/_function_session.py

@@ -983,7 +983,17 @@ def _convert_row_processor_sig(
     if len(signature.parameters) >= 1:
         first_param = next(iter(signature.parameters.values()))
         param_type = first_param.annotation
-        if (param_type == bf_series.Series) or (param_type == pandas.Series):
+        # Type hints for Series inputs should use pandas.Series because the
+        # underlying serialization process converts the input to a string
+        # representation of a pandas Series (not bigframes Series). Using
+        # bigframes Series will lead to TypeError when creating the function
+        # remotely. See more from b/445182819.
+        if param_type == bf_series.Series:
+            raise bf_formatting.create_exception_with_feedback_link(
+                TypeError,
+                "Argument type hint must be Pandas Series, not BigFrames Series.",
+            )
+        if param_type == pandas.Series:
             msg = bfe.format_message("input_types=Series is in preview.")
             warnings.warn(msg, stacklevel=1, category=bfe.PreviewWarning)
             return signature.replace(

bigframes/functions/function_template.py

@@ -363,8 +363,16 @@ def generate_managed_function_code(
                 return {udf_name}(*args)"""
         )
 
-    udf_code_block = textwrap.dedent(
-        f"{udf_code}\n{func_code}\n{bigframes_handler_code}"
-    )
-
-    return udf_code_block
+    udf_code_block = []
+    if not capture_references and is_row_processor:
+        # Enable postponed evaluation of type annotations. This converts all
+        # type hints to strings at runtime, which is necessary for correctly
+        # handling the type annotation of pandas.Series after the UDF code is
+        # serialized for remote execution. See more from b/445182819.
+        udf_code_block.append("from __future__ import annotations")
+
+    udf_code_block.append(udf_code)
+    udf_code_block.append(func_code)
+    udf_code_block.append(bigframes_handler_code)
+
+    return textwrap.dedent("\n".join(udf_code_block))

bigframes/session/__init__.py

@@ -2064,8 +2064,9 @@ def read_gbq_function(
         note, row processor implies that the function has only one input
         parameter.
 
+            >>> import pandas as pd
             >>> @bpd.remote_function(cloud_function_service_account="default")
-            ... def row_sum(s: bpd.Series) -> float:
+            ... def row_sum(s: pd.Series) -> float:
             ...     return s['a'] + s['b'] + s['c']
 
             >>> row_sum_ref = bpd.read_gbq_function(

tests/system/large/functions/test_managed_function.py

@@ -701,8 +701,19 @@ def serialize_row(row):
                 }
             )
 
+        with pytest.raises(
+            TypeError,
+            match="Argument type hint must be Pandas Series, not BigFrames Series.",
+        ):
+            serialize_row_mf = session.udf(
+                input_types=bigframes.series.Series,
+                output_type=str,
+                dataset=dataset_id,
+                name=prefixer.create_prefix(),
+            )(serialize_row)
+
         serialize_row_mf = session.udf(
-            input_types=bigframes.series.Series,
+            input_types=pandas.Series,
             output_type=str,
             dataset=dataset_id,
             name=prefixer.create_prefix(),
@@ -762,7 +773,7 @@ def analyze(row):
         ):
 
             analyze_mf = session.udf(
-                input_types=bigframes.series.Series,
+                input_types=pandas.Series,
                 output_type=str,
                 dataset=dataset_id,
                 name=prefixer.create_prefix(),
@@ -876,7 +887,7 @@ def serialize_row(row):
             )
 
         serialize_row_mf = session.udf(
-            input_types=bigframes.series.Series,
+            input_types=pandas.Series,
             output_type=str,
             dataset=dataset_id,
             name=prefixer.create_prefix(),
@@ -926,7 +937,7 @@ def test_managed_function_df_apply_axis_1_na_nan_inf(dataset_id, session):
 
     try:
 
-        def float_parser(row):
+        def float_parser(row: pandas.Series):
             import numpy as mynp
             import pandas as mypd
 
@@ -937,7 +948,7 @@ def float_parser(row):
             return float(row["text"])
 
         float_parser_mf = session.udf(
-            input_types=bigframes.series.Series,
+            input_types=pandas.Series,
             output_type=float,
             dataset=dataset_id,
             name=prefixer.create_prefix(),
@@ -1027,7 +1038,7 @@ def test_managed_function_df_apply_axis_1_series_args(session, dataset_id, scala
 
     try:
 
-        def analyze(s, x, y):
+        def analyze(s: pandas.Series, x: bool, y: float) -> str:
             value = f"value is {s['int64_col']} and {s['float64_col']}"
             if x:
                 return f"{value}, x is True!"
@@ -1036,8 +1047,6 @@ def analyze(s, x, y):
             return f"{value}, x is False, y is non-positive!"
 
         analyze_mf = session.udf(
-            input_types=[bigframes.series.Series, bool, float],
-            output_type=str,
             dataset=dataset_id,
             name=prefixer.create_prefix(),
         )(analyze)
@@ -1151,7 +1160,7 @@ def is_sum_positive_series(s):
             return s["int64_col"] + s["int64_too"] > 0
 
         is_sum_positive_series_mf = session.udf(
-            input_types=bigframes.series.Series,
+            input_types=pandas.Series,
             output_type=bool,
             dataset=dataset_id,
             name=prefixer.create_prefix(),
@@ -1217,12 +1226,10 @@ def func_for_other(x):
 def test_managed_function_df_where_other_issue(session, dataset_id, scalars_df_index):
     try:
 
-        def the_sum(s):
+        def the_sum(s: pandas.Series) -> int:
             return s["int64_col"] + s["int64_too"]
 
         the_sum_mf = session.udf(
-            input_types=bigframes.series.Series,
-            output_type=int,
             dataset=dataset_id,
             name=prefixer.create_prefix(),
         )(the_sum)

tests/system/large/functions/test_remote_function.py

@@ -1722,7 +1722,7 @@ def serialize_row(row):
             )
 
         serialize_row_remote = session.remote_function(
-            input_types=bigframes.series.Series,
+            input_types=pandas.Series,
             output_type=str,
             reuse=False,
             cloud_function_service_account="default",
@@ -1771,7 +1771,7 @@ def analyze(row):
             )
 
         analyze_remote = session.remote_function(
-            input_types=bigframes.series.Series,
+            input_types=pandas.Series,
             output_type=str,
             reuse=False,
             cloud_function_service_account="default",
@@ -1895,7 +1895,7 @@ def serialize_row(row):
             )
 
         serialize_row_remote = session.remote_function(
-            input_types=bigframes.series.Series,
+            input_types=pandas.Series,
             output_type=str,
             reuse=False,
             cloud_function_service_account="default",
@@ -1944,7 +1944,7 @@ def test_df_apply_axis_1_na_nan_inf(session):
 
     try:
 
-        def float_parser(row):
+        def float_parser(row: pandas.Series):
             import numpy as mynp
             import pandas as mypd
 
@@ -1955,7 +1955,6 @@ def float_parser(row):
             return float(row["text"])
 
         float_parser_remote = session.remote_function(
-            input_types=bigframes.series.Series,
             output_type=float,
             reuse=False,
             cloud_function_service_account="default",
@@ -2055,12 +2054,12 @@ def test_df_apply_axis_1_series_args(session, scalars_dfs):
     try:
 
         @session.remote_function(
-            input_types=[bigframes.series.Series, float, str, bool],
+            input_types=[pandas.Series, float, str, bool],
             output_type=list[str],
             reuse=False,
             cloud_function_service_account="default",
         )
-        def foo_list(x, y0: float, y1, y2) -> list[str]:
+        def foo_list(x: pandas.Series, y0: float, y1, y2) -> list[str]:
             return (
                 [str(x["int64_col"]), str(y0), str(y1), str(y2)]
                 if y2
@@ -3087,12 +3086,21 @@ def test_remote_function_df_where_mask_series(session, dataset_id, scalars_dfs):
     try:
 
         # The return type has to be bool type for callable where condition.
-        def is_sum_positive_series(s):
+        def is_sum_positive_series(s: pandas.Series) -> bool:
             return s["int64_col"] + s["int64_too"] > 0
 
+        with pytest.raises(
+            TypeError,
+            match="Argument type hint must be Pandas Series, not BigFrames Series.",
+        ):
+            session.remote_function(
+                input_types=bigframes.series.Series,
+                dataset=dataset_id,
+                reuse=False,
+                cloud_function_service_account="default",
+            )(is_sum_positive_series)
+
         is_sum_positive_series_mf = session.remote_function(
-            input_types=bigframes.series.Series,
-            output_type=bool,
             dataset=dataset_id,
             reuse=False,
             cloud_function_service_account="default",

tests/system/small/functions/test_remote_function.py

@@ -20,6 +20,7 @@
 import bigframes_vendored.constants as constants
 import google.api_core.exceptions
 from google.cloud import bigquery
+import pandas
 import pandas as pd
 import pyarrow
 import pytest
@@ -1166,16 +1167,14 @@ def test_df_apply_axis_1(session, scalars_dfs, dataset_id_permanent):
     ]
     scalars_df, scalars_pandas_df = scalars_dfs
 
-    def add_ints(row):
+    def add_ints(row: pandas.Series) -> int:
         return row["int64_col"] + row["int64_too"]
 
     with pytest.warns(
         bigframes.exceptions.PreviewWarning,
         match="input_types=Series is in preview.",
     ):
         add_ints_remote = session.remote_function(
-            input_types=bigframes.series.Series,
-            output_type=int,
             dataset=dataset_id_permanent,
             name=get_function_name(add_ints, is_row_processor=True),
             cloud_function_service_account="default",
@@ -1223,11 +1222,11 @@ def test_df_apply_axis_1_ordering(session, scalars_dfs, dataset_id_permanent):
     ordering_columns = ["bool_col", "int64_col"]
     scalars_df, scalars_pandas_df = scalars_dfs
 
-    def add_ints(row):
+    def add_ints(row: pandas.Series) -> int:
         return row["int64_col"] + row["int64_too"]
 
     add_ints_remote = session.remote_function(
-        input_types=bigframes.series.Series,
+        input_types=pandas.Series,
         output_type=int,
         dataset=dataset_id_permanent,
         name=get_function_name(add_ints, is_row_processor=True),
@@ -1267,7 +1266,7 @@ def add_numbers(row):
         return row["x"] + row["y"]
 
     add_numbers_remote = session.remote_function(
-        input_types=bigframes.series.Series,
+        input_types=pandas.Series,
         output_type=float,
         dataset=dataset_id_permanent,
         name=get_function_name(add_numbers, is_row_processor=True),
@@ -1321,7 +1320,7 @@ def echo_len(row):
         return len(row)
 
     echo_len_remote = session.remote_function(
-        input_types=bigframes.series.Series,
+        input_types=pandas.Series,
         output_type=float,
         dataset=dataset_id_permanent,
         name=get_function_name(echo_len, is_row_processor=True),

tests/unit/functions/test_remote_function.py

@@ -17,25 +17,12 @@
 import pandas
 import pytest
 
+import bigframes.exceptions
 import bigframes.functions.function as bff
-import bigframes.series
 from bigframes.testing import mocks
 
 
-@pytest.mark.parametrize(
-    "series_type",
-    (
-        pytest.param(
-            pandas.Series,
-            id="pandas.Series",
-        ),
-        pytest.param(
-            bigframes.series.Series,
-            id="bigframes.series.Series",
-        ),
-    ),
-)
-def test_series_input_types_to_str(series_type):
+def test_series_input_types_to_str():
     """Check that is_row_processor=True uses str as the input type to serialize a row."""
     session = mocks.create_bigquery_session()
     remote_function_decorator = bff.remote_function(
@@ -48,7 +35,7 @@ def test_series_input_types_to_str(series_type):
     ):
 
         @remote_function_decorator
-        def axis_1_function(myparam: series_type) -> str:  # type: ignore
+        def axis_1_function(myparam: pandas.Series) -> str:  # type: ignore
             return "Hello, " + myparam["str_col"] + "!"  # type: ignore
 
     # Still works as a normal function.