Fokko commented on code in PR #245:
URL: https://github.com/apache/iceberg-python/pull/245#discussion_r1441723506
##########
pyiceberg/table/__init__.py:
##########
@@ -1904,3 +1913,200 @@ def _generate_snapshot_id() -> int:
snapshot_id = snapshot_id if snapshot_id >= 0 else snapshot_id * -1
return snapshot_id
+
+class UpdateSpec:
+ _table: Table
+ _schema: Schema
+ _spec: PartitionSpec
+ _name_to_field: Dict[str, PartitionField]
+ _name_to_added_field: Dict[str, PartitionField]
+ _transform_to_field: Dict[Tuple[int, str], PartitionField]
+ _transform_to_added_field: Dict[Tuple[int, str], PartitionField]
+ _case_sensitive: bool
+ _adds: List[PartitionField]
+ _deletes: Set[int]
+ _last_assigned_partition_id: int
+ _renames = Dict[str, str]
+
+ def __init__(
+ self,
+ table: Table,
+ transaction: Optional[Transaction] = None,
+ case_sensitive = True
+ ) -> None:
+ self._table = table
+ self._schema = table.schema()
+ self._spec = table.spec()
+ self._name_to_field = {field.name:field for field in self._spec.fields}
+ self._name_to_added_field = {}
+ self._transform_to_field = {(field.sourceId, repr(field.transform)):
field for field in self._spec.fields}
+ self._transform_to_added_field = {}
+ self._adds = []
+ self._deletes = {}
+ self._last_assigned_partition_id = table.spec().last_assigned_field_id
+ self._renames = {}
+ self._transaction = transaction
+ self._case_sensitive = case_sensitive
+
+
+ def add_field(self, name: str, transform: Transform) -> UpdateSpec:
+ ref = Reference(name)
+ bound_ref = ref.bind(self._schema, self._case_sensitive)
+ # verify transform can actually bind it
+ output_type = bound_ref.field.field_type
+ if not transform.can_transform(output_type):
+ raise ValueError(f"{transform} cannot transform {output_type}
values from {bound_ref.field.name}")
+ transform_key = (bound_ref.field.field_id, transform)
+ existing_partition_field = self._transform_to_field.get(transform)
+ if existing_partition_field and
self._is_duplicate_partition(transform_key[1], existing_partition_field):
+ raise ValueError(f"Duplicate partition field for
${ref.name}=${ref}, ${existing_partition_field} already exists")
+ added = self._transform_to_added_field.get(transform_key)
+ if added:
+ raise ValueError(f"Already added partition {added}")
+ new_field = self._partition_field(transform_key, name)
+ if not new_field.name:
+ new_field.name = _visit(self._schema, new_field,
_PartitionNameGenerator())
+
+ self._check_redundant_partitions(new_field)
+ self._transform_to_added_field[transform_key] = new_field
+
+ existing_partition_field = self._name_to_field.get(new_field.name)
+ if existing_partition_field and not new_field.field_id in
self._deletes:
+ if isinstance(existing_partition_field.transform, VoidTransform):
+ self.rename_field(existing_partition_field.name,
existing_partition_field.name + "_" + existing_partition_field.field_id)
+ else:
+ raise ValueError(f"Cannot add duplicate partition field name:
{existing_partition_field.name}")
+
+ self._name_to_added_field[new_field.name] = new_field
+ self._adds.append(new_field)
+ return self
+
+ def remove_field(self, name: str) -> UpdateSpec:
+ added = self._name_to_added_field.get(name)
+ if added:
+ raise ValueError(f"Cannot delete newly added field {name}")
+ renamed = self._renames.get(name)
+ if renamed:
+ raise ValueError(f"Cannot rename and delete field: {name}")
+ field = self._name_to_field.get(name)
+ if not field:
+ raise ValueError(f"No such partition field: {name}")
+
+ self._deletes.add(field.field_id)
+ return self
+
+ def rename_field(self, name: str, new_name: str) -> UpdateSpec:
+ existing_field = self._name_to_field.get(new_name)
+ if existing_field and isinstance(existing_field.transform,
VoidTransform):
+ return self.rename_field(name, name + "_" +
existing_field.field_id)
+ added = self._name_to_added_field.get(name)
+ if added:
+ raise ValueError(f"Cannot rename recently added partitions")
+ field = self._name_to_field.get(name)
+ if not field:
+ raise ValueError(f"Cannot find partition field {name}")
+ if field.field_id in self._deletes:
+ raise ValueError(f"Cannot delete and rename partition field
{name}")
+ self._renames[name] = new_name
+ return self
+
+ def commit(self):
Review Comment:
For the schema, we have a context-manager, which adds a nice touch to the
API:
```python
def __exit__(self, _: Any, value: Any, traceback: Any) -> None:
"""Close and commit the change."""
return self.commit()
def __enter__(self) -> UpdateSchema:
"""Update the table."""
return self
```
This allows you to use the `with ..`:
```python
with table.update_schema() as update:
update.add_column("some_field", IntegerType(), "doc")
```
--
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: issues-unsubscr...@iceberg.apache.org
For queries about this service, please contact Infrastructure at:
us...@infra.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscr...@iceberg.apache.org
For additional commands, e-mail: issues-h...@iceberg.apache.org
