Source code for airflow.contrib.operators.gcs_list_operator
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from typing import Iterable
from airflow.contrib.hooks.gcs_hook import GoogleCloudStorageHook
from airflow.models import BaseOperator
from airflow.utils.decorators import apply_defaults
[docs]class GoogleCloudStorageListOperator(BaseOperator):
"""
List all objects from the bucket with the give string prefix and delimiter in name.
This operator returns a python list with the name of objects which can be used by
`xcom` in the downstream task.
:param bucket: The Google cloud storage bucket to find the objects. (templated)
:type bucket: str
:param prefix: Prefix string which filters objects whose name begin with
this prefix. (templated)
:type prefix: str
:param delimiter: The delimiter by which you want to filter the objects. (templated)
For e.g to lists the CSV files from in a directory in GCS you would use
delimiter='.csv'.
:type delimiter: str
:param google_cloud_storage_conn_id: The connection ID to use when
connecting to Google cloud storage.
:type google_cloud_storage_conn_id: str
:param delegate_to: The account to impersonate, if any.
For this to work, the service account making the request must have
domain-wide delegation enabled.
:type delegate_to: str
**Example**:
The following Operator would list all the Avro files from ``sales/sales-2017``
folder in ``data`` bucket. ::
GCS_Files = GoogleCloudStorageListOperator(
task_id='GCS_Files',
bucket='data',
prefix='sales/sales-2017/',
delimiter='.avro',
google_cloud_storage_conn_id=google_cloud_conn_id
)
"""
[docs] template_fields = ('bucket', 'prefix', 'delimiter') # type: Iterable[str]
@apply_defaults
def __init__(self,
bucket,
prefix=None,
delimiter=None,
google_cloud_storage_conn_id='google_cloud_default',
delegate_to=None,
*args,
**kwargs):
super(GoogleCloudStorageListOperator, self).__init__(*args, **kwargs)
self.bucket = bucket
self.prefix = prefix
self.delimiter = delimiter
self.google_cloud_storage_conn_id = google_cloud_storage_conn_id
self.delegate_to = delegate_to
[docs] def execute(self, context):
hook = GoogleCloudStorageHook(
google_cloud_storage_conn_id=self.google_cloud_storage_conn_id,
delegate_to=self.delegate_to
)
self.log.info('Getting list of the files. Bucket: %s; Delimiter: %s; Prefix: %s',
self.bucket, self.delimiter, self.prefix)
return hook.list(bucket=self.bucket,
prefix=self.prefix,
delimiter=self.delimiter)