Fokko commented on code in PR #4685:
URL: https://github.com/apache/iceberg/pull/4685#discussion_r872639988


##########
python/src/iceberg/schema.py:
##########
@@ -497,31 +530,78 @@ def index_name_by_id(schema_or_type) -> Dict[int, str]:
     return indexer.by_id()
 
 
-class _BuildPositionAccessors(SchemaVisitor[Dict[int, "Accessor"]]):
-    """A schema visitor for generating a field ID to accessor index"""
+Position = int
 
-    def __init__(self) -> None:
-        self._index: Dict[int, Accessor] = {}
 
-    def schema(self, schema, result: Dict[int, Accessor]) -> Dict[int, 
Accessor]:
-        return self._index
+class _BuildPositionAccessors(SchemaVisitor[Dict[Position, Accessor]]):
+    """A schema visitor for generating a field ID to accessor index
 
-    def struct(self, struct, result: List[Dict[int, Accessor]]) -> Dict[int, 
Accessor]:
-        # TODO: Populate the `self._index` dictionary where the key is the 
field ID and the value is an accessor for that field.
-        #   The equivalent java logic can be found here: 
https://github.com/apache/iceberg/blob/master/api/src/main/java/org/apache/iceberg/Accessors.java#L213-L230
-        return self._index
+    Example:
+        >>> from iceberg.schema import Schema
+        >>> from iceberg.types import *
+        >>> schema = Schema(
+        ...     NestedField(field_id=2, name="id", field_type=IntegerType(), 
is_optional=False),
+        ...     NestedField(field_id=1, name="data", field_type=StringType(), 
is_optional=True),
+        ...     NestedField(
+        ...         field_id=3,
+        ...         name="location",
+        ...         field_type=StructType(
+        ...             NestedField(field_id=5, name="latitude", 
field_type=FloatType(), is_optional=False),
+        ...             NestedField(field_id=6, name="longitude", 
field_type=FloatType(), is_optional=False),
+        ...         ),
+        ...         is_optional=True,
+        ...     ),
+        ...     schema_id=1,
+        ...     identifier_field_ids=[1],
+        ... )
+        >>> result = build_position_accessors(schema)
+        >>> expected = {
+        ...      2: Accessor(position=0, inner=None),
+        ...      1: Accessor(position=1, inner=None),
+        ...      5: Accessor(position=2, inner=Accessor(position=0, 
inner=None)),
+        ...      6: Accessor(position=2, inner=Accessor(position=1, 
inner=None)),
+        ... }
+        >>> result == expected
+        True
+    """
 
-    def field(self, field: NestedField, result: Dict[int, Accessor]) -> 
Dict[int, Accessor]:
-        return self._index
+    @staticmethod
+    def _wrap_leaves(result: Dict[Position, Accessor], position: Position = 0) 
-> Dict[Position, Accessor]:
+        return {field_id: Accessor(position, inner=inner) for field_id, inner 
in result.items()}
 
-    def list(self, list_type: ListType, result: Dict[int, Accessor]) -> 
Dict[int, Accessor]:
-        return self._index
+    def schema(self, schema: Schema, result: Dict[Position, Accessor]) -> 
Dict[Position, Accessor]:
+        return result
 
-    def map(self, map_type: MapType, key_result: Dict[int, Accessor], 
value_result: Dict[int, Accessor]) -> Dict[int, Accessor]:
-        return self._index
+    def struct(self, struct: StructType, field_results: List[Dict[Position, 
Accessor]]) -> Dict[Position, Accessor]:
+        result = {}
 
-    def primitive(self, primitive: PrimitiveType) -> Dict[int, Accessor]:
-        return self._index
+        for position, field in enumerate(struct.fields):
+            if field_results[position]:

Review Comment:
   @rdblue Interesting case, and I see your point, just updated the code and 
extended the test cases 👍🏻 



-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]


---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to