def unmap_dataset(
project: Project,
*,
source_dataset: Dataset,
remove_dataset_from_project: bool = False,
skip_if_missing: bool = False,
) -> None:
"""
Wholly unmaps a dataset and optionally removes it from a project.
Args:
source_dataset: the source dataset (Dataset object not a string) to unmap
project: the project in which to unmap the dataset
remove_dataset_from_project: boolean to also remove the dataset from the project
skip_if_missing: boolean to skip if dataset is not in project. If set to false and
dataset is not in project will raise a RuntimeError
Returns:
None
Raises:
RuntimeError: if `source_dataset` is not in `project` and `skip_if_missing` not set to True
"""
# check to make sure dataset is in project and log a warning if it is not
if source_dataset.name not in [x.name for x in project.input_datasets()]:
if skip_if_missing:
LOGGER.warning(
f"Dataset to unmap {source_dataset.name} not in project {project.name}! "
f"However skip_if_missing flag is set so will do nothing"
)
return None
else:
error_message = (
f"Dataset to unmap {source_dataset.name} not in project "
f"{project.name} and skip_if_missing not set to True so failing! "
)
LOGGER.error(error_message)
raise RuntimeError(error_message)
# the resource ids of attribute mappings unfortunately change when you delete one
# so need to just do this until there are no mappings left for the source dataset of interest
while True:
mappings = [
x
for x in project.attribute_mappings().stream()
if x.input_dataset_name == source_dataset.name
]
# if no mappings found for this dataset then break
if not mappings:
break
for mapping in mappings:
# can only delete one then have to break out of inner loop
project.attribute_mappings().delete_by_resource_id(mapping.resource_id)
break
# optionally remove dataset from the project
if remove_dataset_from_project:
project.remove_input_dataset(source_dataset)
def unmap_attribute(
project: Project,
*,
source_attribute_name: str,
source_dataset_name: str,
unified_attribute_name: str,
) -> None:
"""
Unmaps a source attribute.
Args:
source_attribute_name: the name of the source attribute to unmap
source_dataset_name: the name of the source dataset containing that source attribute
unified_attribute_name: the unified attribute from which to unmap
project: the project in which to unmap the attribute
Returns:
None
"""
LOGGER.info(
f"Trying to remove mapping of source attribute {source_attribute_name} in dataset "
f"{source_dataset_name} from unified attribute {unified_attribute_name}"
)
# get mapping collection
mapping_collection = project.attribute_mappings()
# run through and get the resource id of the mapping to remove
resource_id_to_remove = None
for mapping in mapping_collection.stream():
# consider it match if all of source attribute, source dataset and unified attribute
# are equal
if (
source_attribute_name == mapping.input_attribute_name
and source_dataset_name == mapping.input_dataset_name
and unified_attribute_name == mapping.unified_attribute_name
):
resource_id_to_remove = mapping.resource_id
break
# log warning if resource id wasn't found
if resource_id_to_remove is None:
LOGGER.warning(
f"Mapping of {source_attribute_name} in dataset {source_dataset_name} to "
f"unified attribute {unified_attribute_name} not found!"
)
# if found remove it
else:
mapping_collection.delete_by_resource_id(resource_id_to_remove)
def map_attribute(
project: Project,
*,
source_attribute_name: str,
source_dataset_name: str,
unified_attribute_name: str,
) -> AttributeMapping:
"""
Maps source_attribute in source_dataset to unified_attribute in unified_dataset.
If the mapping already exists it will log
a warning and return the existing AttributeMapping from the project's collection.
Args:
source_attribute_name: Source attribute name to map
source_dataset_name: Source dataset containing the source attribute
unified_attribute_name: Unified attribute to which to map the source attribute
project: The project in which to perform the mapping
Returns:
AttributeMapping that was created
Raises:
ValueError: if input variables `source_attribute_name` or `source_dataset_name` or
`unified_attribute_name` are set to empty strings;
or if the dataset `source_dataset_name` is not found on Tamr;
or if `source_attribute_name` is missing from the attributes of `source_attribute_name`
"""
# simple validation, nothing should be empty
variables = [source_attribute_name, source_dataset_name, unified_attribute_name]
empty_variables = [x for x in variables if x == ""]
if empty_variables:
empty_variable_string = ", ".join(empty_variables)
error_message = (
f"The following variables are set to empty strings and "
f"need to be filled in: {empty_variable_string} !"
)
LOGGER.error(error_message)
raise ValueError(error_message)
# also validate that the dataset exists and has this column
try:
source_dataset = project.client.datasets.by_name(source_dataset_name)
except KeyError:
error_msg = f"Dataset {source_dataset_name} not found!"
LOGGER.error(error_msg)
raise ValueError(error_msg)
try:
assert source_attribute_name in [x.name for x in source_dataset.attributes]
except AssertionError:
error_msg = f"Attribute {source_attribute_name} not found in {source_dataset_name}!"
LOGGER.error(error_msg)
raise ValueError(error_msg)
# generate mapping spec
mapping_spec = _get_mapping_spec_for_ud(
source_attr_name=source_attribute_name,
source_ds_name=source_dataset_name,
unified_attr_name=unified_attribute_name,
unified_ds_name=project.unified_dataset().name,
)
# add the mapping to the project's collection - this is what does the actual mapping
try:
return project.attribute_mappings().create(mapping_spec.to_dict())
except JSONDecodeError as e:
# can get a jsondecode error if the attribute is already mapped.
# If it is, then log a warning and return empty mapping
# if it is not already mapped break loudly
m: AttributeMapping
for m in project.attribute_mappings().stream():
if (
m.input_dataset_name == source_dataset_name
and m.input_attribute_name == source_attribute_name
and m.unified_attribute_name == unified_attribute_name
):
# mapping exists, log warning and return existing mapping
LOGGER.warning(
f"mapping of attribute {source_attribute_name} in dataset "
f"{source_dataset_name} to unified attribute {unified_attribute_name} "
f"already exists! Returning existing mapping spec"
)
return m
# if haven't returned then throw the JSONDecodeError
raise e