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Posted to commits@beam.apache.org by bh...@apache.org on 2022/07/01 19:04:39 UTC

[beam] branch master updated: Python: Use RowTypeConstraint for normalizing all schema-inferrable user types (#22066)

This is an automated email from the ASF dual-hosted git repository.

bhulette pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/beam.git


The following commit(s) were added to refs/heads/master by this push:
     new 07658c6cce9 Python: Use RowTypeConstraint for normalizing all schema-inferrable user types (#22066)
07658c6cce9 is described below

commit 07658c6cce9dd82c59b5e521e08150b2df443391
Author: Brian Hulette <bh...@google.com>
AuthorDate: Fri Jul 1 12:04:31 2022 -0700

    Python: Use RowTypeConstraint for normalizing all schema-inferrable user types (#22066)
    
    * Use RowTypeConstraint for normalizing schema-inferrable user types
    
    * Fix user_type generation for nested rows
    
    * Fix docstring
    
    * Backout sdk_options changes
    
    * fix import
    
    * Backout sql_test changes
    
    * cleanup
    
    * Update sdks/python/apache_beam/typehints/schemas.py
    
    Co-authored-by: Andy Ye <an...@gmail.com>
    
    * Address review comments
    
    * yapf
    
    * Clarify docstring
    
    Co-authored-by: Andy Ye <an...@gmail.com>
---
 sdks/python/apache_beam/typehints/row_type.py      |  85 +++++++++++-
 sdks/python/apache_beam/typehints/schemas.py       |  89 +++++++------
 sdks/python/apache_beam/typehints/schemas_test.py  | 146 ++++++++++++---------
 .../apache_beam/typehints/trivial_inference.py     |   9 +-
 4 files changed, 218 insertions(+), 111 deletions(-)

diff --git a/sdks/python/apache_beam/typehints/row_type.py b/sdks/python/apache_beam/typehints/row_type.py
index f7098fb9067..37e52c62a2e 100644
--- a/sdks/python/apache_beam/typehints/row_type.py
+++ b/sdks/python/apache_beam/typehints/row_type.py
@@ -17,19 +17,98 @@
 
 # pytype: skip-file
 
+from __future__ import annotations
+
+from typing import List
+from typing import Optional
+from typing import Sequence
+from typing import Tuple
+
 from apache_beam.typehints import typehints
+from apache_beam.typehints.native_type_compatibility import match_is_named_tuple
+
+# Name of the attribute added to user types (existing and generated) to store
+# the corresponding schema ID
+_BEAM_SCHEMA_ID = "_beam_schema_id"
 
 
 class RowTypeConstraint(typehints.TypeConstraint):
-  def __init__(self, fields):
-    self._fields = tuple(fields)
+  def __init__(self, fields: List[Tuple[str, type]], user_type=None):
+    """For internal use only, no backwards comatibility guaratees.  See
+    https://beam.apache.org/documentation/programming-guide/#schemas-for-pl-types
+    for guidance on creating PCollections with inferred schemas.
+
+    Note RowTypeConstraint does not currently store arbitrary functions for
+    converting to/from the user type. Instead, we only support ``NamedTuple``
+    user types and make the follow assumptions:
+
+    - The user type can be constructed with field values as arguments in order
+      (i.e. ``constructor(*field_values)``).
+    - Field values can be accessed from instances of the user type by attribute
+      (i.e. with ``getattr(obj, field_name)``).
+
+    In the future we will add support for dataclasses
+    ([#22085](https://github.com/apache/beam/issues/22085)) which also satisfy
+    these assumptions.
+
+    The RowTypeConstraint constructor should not be called directly (even
+    internally to Beam). Prefer static methods ``from_user_type`` or
+    ``from_fields``.
+
+    Parameters:
+      fields: a list of (name, type) tuples, representing the schema inferred
+        from user_type.
+      user_type: constructor for a user type (e.g. NamedTuple class) that is
+        used to represent this schema in user code.
+    """
+    # Recursively wrap row types in a RowTypeConstraint
+    self._fields = tuple((name, RowTypeConstraint.from_user_type(typ) or typ)
+                         for name,
+                         typ in fields)
+
+    self._user_type = user_type
+
+    # Note schema ID can be None if the schema is not registered yet.
+    # Currently registration happens when converting to schema protos, in
+    # apache_beam.typehints.schemas
+    if self._user_type is not None:
+      self._schema_id = getattr(self._user_type, _BEAM_SCHEMA_ID, None)
+    else:
+      self._schema_id = None
+
+  @staticmethod
+  def from_user_type(user_type: type) -> Optional[RowTypeConstraint]:
+    if match_is_named_tuple(user_type):
+      fields = [(name, user_type.__annotations__[name])
+                for name in user_type._fields]
+
+      return RowTypeConstraint(fields=fields, user_type=user_type)
+
+    return None
+
+  @staticmethod
+  def from_fields(fields: Sequence[Tuple[str, type]]) -> RowTypeConstraint:
+    return RowTypeConstraint(fields=fields, user_type=None)
+
+  @property
+  def user_type(self):
+    return self._user_type
+
+  def set_schema_id(self, schema_id):
+    self._schema_id = schema_id
+    if self._user_type is not None:
+      setattr(self._user_type, _BEAM_SCHEMA_ID, self._schema_id)
+
+  @property
+  def schema_id(self):
+    return self._schema_id
 
   def _consistent_with_check_(self, sub):
     return self == sub
 
   def type_check(self, instance):
     from apache_beam import Row
-    return isinstance(instance, Row)
+    return isinstance(instance, (Row, self._user_type))
 
   def _inner_types(self):
     """Iterates over the inner types of the composite type."""
diff --git a/sdks/python/apache_beam/typehints/schemas.py b/sdks/python/apache_beam/typehints/schemas.py
index 74ace0e319a..6f56d2a6fa4 100644
--- a/sdks/python/apache_beam/typehints/schemas.py
+++ b/sdks/python/apache_beam/typehints/schemas.py
@@ -145,10 +145,6 @@ PRIMITIVE_TO_ATOMIC_TYPE.update({
     float: schema_pb2.DOUBLE,
 })
 
-# Name of the attribute added to user types (existing and generated) to store
-# the corresponding schema ID
-_BEAM_SCHEMA_ID = "_beam_schema_id"
-
 
 def named_fields_to_schema(names_and_types):
   # type: (Union[Dict[str, type], Sequence[Tuple[str, type]]]) -> schema_pb2.Schema # noqa: F821
@@ -191,46 +187,43 @@ class SchemaTranslation(object):
     if isinstance(type_, schema_pb2.Schema):
       return schema_pb2.FieldType(row_type=schema_pb2.RowType(schema=type_))
 
-    elif match_is_named_tuple(type_):
-      if hasattr(type_, _BEAM_SCHEMA_ID):
-        schema_id = getattr(type_, _BEAM_SCHEMA_ID)
-        schema = self.schema_registry.get_schema_by_id(
-            getattr(type_, _BEAM_SCHEMA_ID))
-      else:
-        schema_id = self.schema_registry.generate_new_id()
+    if isinstance(type_, row_type.RowTypeConstraint):
+      if type_.schema_id is None:
+        schema_id = SCHEMA_REGISTRY.generate_new_id()
+        type_.set_schema_id(schema_id)
         schema = None
-        setattr(type_, _BEAM_SCHEMA_ID, schema_id)
+      else:
+        schema_id = type_.schema_id
+        schema = self.schema_registry.get_schema_by_id(schema_id)
 
       if schema is None:
-        fields = [
-            schema_pb2.Field(
-                name=name,
-                type=typing_to_runner_api(type_.__annotations__[name]))
-            for name in type_._fields
-        ]
-        schema = schema_pb2.Schema(fields=fields, id=schema_id)
-        self.schema_registry.add(type_, schema)
-
+        # Either user_type was not annotated with a schema id, or there was
+        # no schema in the registry with the id. The latter should only happen
+        # in tests.
+        # Either way, we need to generate a new schema proto.
+        schema = schema_pb2.Schema(
+            fields=[
+                schema_pb2.Field(
+                    name=name, type=self.typing_to_runner_api(field_type))
+                for (name, field_type) in type_._fields
+            ],
+            id=schema_id)
+        self.schema_registry.add(type_.user_type, schema)
       return schema_pb2.FieldType(row_type=schema_pb2.RowType(schema=schema))
-
-    elif isinstance(type_, row_type.RowTypeConstraint):
-      return schema_pb2.FieldType(
-          row_type=schema_pb2.RowType(
-              schema=schema_pb2.Schema(
-                  fields=[
-                      schema_pb2.Field(
-                          name=name, type=typing_to_runner_api(field_type))
-                      for (name, field_type) in type_._fields
-                  ],
-                  id=self.schema_registry.generate_new_id())))
+    else:
+      # See if this is coercible to a RowTypeConstraint (e.g. a NamedTuple or
+      # dataclass)
+      row_type_constraint = row_type.RowTypeConstraint.from_user_type(type_)
+      if row_type_constraint is not None:
+        return self.typing_to_runner_api(row_type_constraint)
 
     # All concrete types (other than NamedTuple sub-classes) should map to
     # a supported primitive type.
-    elif type_ in PRIMITIVE_TO_ATOMIC_TYPE:
+    if type_ in PRIMITIVE_TO_ATOMIC_TYPE:
       return schema_pb2.FieldType(atomic_type=PRIMITIVE_TO_ATOMIC_TYPE[type_])
 
     elif _match_is_exactly_mapping(type_):
-      key_type, value_type = map(typing_to_runner_api, _get_args(type_))
+      key_type, value_type = map(self.typing_to_runner_api, _get_args(type_))
       return schema_pb2.FieldType(
           map_type=schema_pb2.MapType(key_type=key_type, value_type=value_type))
 
@@ -238,17 +231,17 @@ class SchemaTranslation(object):
       # It's possible that a user passes us Optional[Optional[T]], but in python
       # typing this is indistinguishable from Optional[T] - both resolve to
       # Union[T, None] - so there's no need to check for that case here.
-      result = typing_to_runner_api(extract_optional_type(type_))
+      result = self.typing_to_runner_api(extract_optional_type(type_))
       result.nullable = True
       return result
 
     elif _safe_issubclass(type_, Sequence):
-      element_type = typing_to_runner_api(_get_args(type_)[0])
+      element_type = self.typing_to_runner_api(_get_args(type_)[0])
       return schema_pb2.FieldType(
           array_type=schema_pb2.ArrayType(element_type=element_type))
 
     elif _safe_issubclass(type_, Mapping):
-      key_type, value_type = map(typing_to_runner_api, _get_args(type_))
+      key_type, value_type = map(self.typing_to_runner_api, _get_args(type_))
       return schema_pb2.FieldType(
           map_type=schema_pb2.MapType(key_type=key_type, value_type=value_type))
 
@@ -264,7 +257,7 @@ class SchemaTranslation(object):
       return schema_pb2.FieldType(
           logical_type=schema_pb2.LogicalType(
               urn=logical_type.urn(),
-              representation=typing_to_runner_api(
+              representation=self.typing_to_runner_api(
                   logical_type.representation_type())))
 
   def typing_from_runner_api(
@@ -297,8 +290,12 @@ class SchemaTranslation(object):
           self.typing_from_runner_api(fieldtype_proto.map_type.value_type)]
     elif type_info == "row_type":
       schema = fieldtype_proto.row_type.schema
+      # First look for user type in the registry
       user_type = self.schema_registry.get_typing_by_id(schema.id)
+
       if user_type is None:
+        # If not in SDK options (the coder likely came from another SDK),
+        # generate a NamedTuple type to use.
         from apache_beam import coders
 
         type_name = 'BeamSchema_{}'.format(schema.id.replace('-', '_'))
@@ -307,6 +304,8 @@ class SchemaTranslation(object):
         for field in schema.fields:
           try:
             field_py_type = self.typing_from_runner_api(field.type)
+            if isinstance(field_py_type, row_type.RowTypeConstraint):
+              field_py_type = field_py_type.user_type
           except ValueError as e:
             raise ValueError(
                 "Failed to decode schema due to an issue with Field proto:\n\n"
@@ -316,8 +315,6 @@ class SchemaTranslation(object):
 
         user_type = NamedTuple(type_name, subfields)
 
-        setattr(user_type, _BEAM_SCHEMA_ID, schema.id)
-
         # Define a reduce function, otherwise these types can't be pickled
         # (See BEAM-9574)
         def __reduce__(self):
@@ -329,7 +326,11 @@ class SchemaTranslation(object):
 
         self.schema_registry.add(user_type, schema)
         coders.registry.register_coder(user_type, coders.RowCoder)
-      return user_type
+        result = row_type.RowTypeConstraint.from_user_type(user_type)
+        result.set_schema_id(schema.id)
+        return result
+      else:
+        return row_type.RowTypeConstraint.from_user_type(user_type)
 
     elif type_info == "logical_type":
       if fieldtype_proto.logical_type.urn == PYTHON_ANY_URN:
@@ -349,9 +350,11 @@ def _hydrate_namedtuple_instance(encoded_schema, values):
 
 def named_tuple_from_schema(
     schema, schema_registry: SchemaTypeRegistry = SCHEMA_REGISTRY) -> type:
-  return typing_from_runner_api(
+  row_type_constraint = typing_from_runner_api(
       schema_pb2.FieldType(row_type=schema_pb2.RowType(schema=schema)),
-      schema_registry)
+      schema_registry=schema_registry)
+  assert isinstance(row_type_constraint, row_type.RowTypeConstraint)
+  return row_type_constraint.user_type
 
 
 def named_tuple_to_schema(
diff --git a/sdks/python/apache_beam/typehints/schemas_test.py b/sdks/python/apache_beam/typehints/schemas_test.py
index 404d9c5583c..24ec9d11fa5 100644
--- a/sdks/python/apache_beam/typehints/schemas_test.py
+++ b/sdks/python/apache_beam/typehints/schemas_test.py
@@ -30,9 +30,11 @@ from typing import Optional
 from typing import Sequence
 
 import numpy as np
+from parameterized import parameterized
 
 from apache_beam.portability import common_urns
 from apache_beam.portability.api import schema_pb2
+from apache_beam.typehints import row_type
 from apache_beam.typehints.native_type_compatibility import match_is_named_tuple
 from apache_beam.typehints.schemas import SchemaTypeRegistry
 from apache_beam.typehints.schemas import named_tuple_from_schema
@@ -41,6 +43,59 @@ from apache_beam.typehints.schemas import typing_from_runner_api
 from apache_beam.typehints.schemas import typing_to_runner_api
 from apache_beam.utils.timestamp import Timestamp
 
+all_nonoptional_primitives = [
+    np.int8,
+    np.int16,
+    np.int32,
+    np.int64,
+    np.float32,
+    np.float64,
+    bool,
+    bytes,
+    str,
+]
+
+all_optional_primitives = [Optional[typ] for typ in all_nonoptional_primitives]
+
+all_primitives = all_nonoptional_primitives + all_optional_primitives
+
+basic_array_types = [Sequence[typ] for typ in all_primitives]
+
+basic_map_types = [
+    Mapping[key_type, value_type] for key_type,
+    value_type in itertools.product(all_primitives, all_primitives)
+]
+
+
+class AllPrimitives(NamedTuple):
+  field_int8: np.int8
+  field_int16: np.int16
+  field_int32: np.int32
+  field_int64: np.int64
+  field_float32: np.float32
+  field_float64: np.float64
+  field_bool: bool
+  field_bytes: bytes
+  field_str: str
+  field_optional_int8: Optional[np.int8]
+  field_optional_int16: Optional[np.int16]
+  field_optional_int32: Optional[np.int32]
+  field_optional_int64: Optional[np.int64]
+  field_optional_float32: Optional[np.float32]
+  field_optional_float64: Optional[np.float64]
+  field_optional_bool: Optional[bool]
+  field_optional_bytes: Optional[bytes]
+  field_optional_str: Optional[str]
+
+
+class ComplexSchema(NamedTuple):
+  id: np.int64
+  name: str
+  optional_map: Optional[Mapping[str, Optional[np.float64]]]
+  optional_array: Optional[Sequence[np.float32]]
+  array_optional: Sequence[Optional[bool]]
+  timestamp: Timestamp
+
 
 class SchemaTest(unittest.TestCase):
   """ Tests for Runner API Schema proto to/from typing conversions
@@ -50,68 +105,27 @@ class SchemaTest(unittest.TestCase):
   are cached by ID, so performing just one of them wouldn't necessarily exercise
   all code paths.
   """
-  def test_typing_survives_proto_roundtrip(self):
-    all_nonoptional_primitives = [
-        np.int8,
-        np.int16,
-        np.int32,
-        np.int64,
-        np.float32,
-        np.float64,
-        bool,
-        bytes,
-        str,
-    ]
-
-    all_optional_primitives = [
-        Optional[typ] for typ in all_nonoptional_primitives
-    ]
-
-    all_primitives = all_nonoptional_primitives + all_optional_primitives
-
-    basic_array_types = [Sequence[typ] for typ in all_primitives]
-
-    basic_map_types = [
-        Mapping[key_type, value_type] for key_type,
-        value_type in itertools.product(all_primitives, all_primitives)
-    ]
-
-    selected_schemas = [
-        NamedTuple(
-            'AllPrimitives',
-            [('field%d' % i, typ) for i, typ in enumerate(all_primitives)]),
-        NamedTuple(
-            'ComplexSchema',
-            [
-                ('id', np.int64),
-                ('name', str),
-                ('optional_map', Optional[Mapping[str, Optional[np.float64]]]),
-                ('optional_array', Optional[Sequence[np.float32]]),
-                ('array_optional', Sequence[Optional[bool]]),
-                ('timestamp', Timestamp),
-            ])
-    ]
+  @parameterized.expand([(user_type,) for user_type in
+      all_primitives + \
+      basic_array_types + \
+      basic_map_types]
+                        )
+  def test_typing_survives_proto_roundtrip(self, user_type):
+    self.assertEqual(
+        user_type,
+        typing_from_runner_api(
+            typing_to_runner_api(
+                user_type, schema_registry=SchemaTypeRegistry()),
+            schema_registry=SchemaTypeRegistry()))
 
-    test_cases = all_primitives + \
-                 basic_array_types + \
-                 basic_map_types
+  @parameterized.expand([(AllPrimitives, ), (ComplexSchema, )])
+  def test_namedtuple_roundtrip(self, user_type):
+    roundtripped = typing_from_runner_api(
+        typing_to_runner_api(user_type, schema_registry=SchemaTypeRegistry()),
+        schema_registry=SchemaTypeRegistry())
 
-    for test_case in test_cases:
-      self.assertEqual(
-          test_case,
-          typing_from_runner_api(
-              typing_to_runner_api(
-                  test_case, schema_registry=SchemaTypeRegistry()),
-              schema_registry=SchemaTypeRegistry()))
-
-    # Break out NamedTuple types since they require special verification
-    for test_case in selected_schemas:
-      self.assert_namedtuple_equivalent(
-          test_case,
-          typing_from_runner_api(
-              typing_to_runner_api(
-                  test_case, schema_registry=SchemaTypeRegistry()),
-              schema_registry=SchemaTypeRegistry()))
+    self.assertIsInstance(roundtripped, row_type.RowTypeConstraint)
+    self.assert_namedtuple_equivalent(roundtripped.user_type, user_type)
 
   def assert_namedtuple_equivalent(self, actual, expected):
     # Two types are only considered equal if they are literally the same
@@ -124,9 +138,16 @@ class SchemaTest(unittest.TestCase):
     self.assertTrue(match_is_named_tuple(expected))
     self.assertTrue(match_is_named_tuple(actual))
 
+    # TODO(https://github.com/apache/beam/issues/22082): This will break for
+    # nested complex types.
     self.assertEqual(actual.__annotations__, expected.__annotations__)
 
-    self.assertEqual(dir(actual), dir(expected))
+    # TODO(https://github.com/apache/beam/issues/22082): Serialize user_type and
+    # re-hydrate with sdk_options to make these checks pass.
+    #self.assertEqual(dir(actual), dir(expected))
+    #
+    #for attr in dir(expected):
+    #  self.assertEqual(getattr(actual, attr), getattr(expected, attr))
 
   def test_proto_survives_typing_roundtrip(self):
     all_nonoptional_primitives = [
@@ -253,7 +274,8 @@ class SchemaTest(unittest.TestCase):
             schema_pb2.FieldType(
                 logical_type=schema_pb2.LogicalType(
                     urn=common_urns.python_callable.urn,
-                    representation=typing_to_runner_api(str)))),
+                    representation=typing_to_runner_api(str))),
+            schema_registry=SchemaTypeRegistry()),
         PythonCallableWithSource)
 
   def test_trivial_example(self):
diff --git a/sdks/python/apache_beam/typehints/trivial_inference.py b/sdks/python/apache_beam/typehints/trivial_inference.py
index 14df8e79439..4de89ffd83b 100644
--- a/sdks/python/apache_beam/typehints/trivial_inference.py
+++ b/sdks/python/apache_beam/typehints/trivial_inference.py
@@ -49,7 +49,7 @@ def instance_to_type(o):
   if o is None:
     return type(None)
   elif t == pvalue.Row:
-    return row_type.RowTypeConstraint([
+    return row_type.RowTypeConstraint.from_fields([
         (name, instance_to_type(value)) for name, value in o.as_dict().items()
     ])
   elif t not in typehints.DISALLOWED_PRIMITIVE_TYPES:
@@ -438,8 +438,11 @@ def infer_return_type_func(f, input_types, debug=False, depth=0):
           from apache_beam.pvalue import Row
           if state.stack[-pop_count].value == Row:
             fields = state.stack[-1].value
-            return_type = row_type.RowTypeConstraint(
-                zip(fields, Const.unwrap_all(state.stack[-pop_count + 1:-1])))
+            return_type = row_type.RowTypeConstraint.from_fields(
+                list(
+                    zip(
+                        fields,
+                        Const.unwrap_all(state.stack[-pop_count + 1:-1]))))
           else:
             return_type = Any
         else: