Source code for

import google
from import storage
from import setup_google_application_credentials
from parsons.utilities import files
import logging

logger = logging.getLogger(__name__)

[docs]class GoogleCloudStorage(object): """ This class requires application credentials in the form of a json. It can be passed in the following ways: * Set an environmental variable named ``GOOGLE_APPLICATION_CREDENTIALS`` with the local path to the credentials json. Example: ``GOOGLE_APPLICATION_CREDENTALS='path/to/creds.json'`` * Pass in the path to the credentials using the ``app_creds`` argument. * Pass in a json string using the ``app_creds`` argument. `Args:` credentials: str A credentials json string or a path to a json file. Not required if ``GOOGLE_APPLICATION_CREDENTIALS`` env variable set. project: str The project which the client is acting on behalf of. If not passed then will use the default inferred environment. `Returns:` GoogleCloudStorage Class """ def __init__(self, app_creds=None, project=None): setup_google_application_credentials(app_creds) # Throws an error if you pass project=None, so adding if/else statement. if not project: self.client = storage.Client() """ Access all methods of `` package """ else: self.client = storage.Client(project=project)
[docs] def list_buckets(self): """ Returns a list of buckets `Returns:` List of buckets """ buckets = [ for b in self.client.list_buckets()]'Found {len(buckets)}.') return buckets
[docs] def bucket_exists(self, bucket_name): """ Verify that a bucket exists `Args:` bucket_name: str The name of the bucket `Returns:` boolean """ if bucket_name in self.list_buckets():'{bucket_name} exists.') return True else:'{bucket_name} does not exist.') return False
[docs] def get_bucket(self, bucket_name): """ Returns a bucket object `Args:` bucket_name: str The name of bucket `Returns:` GoogleCloud Storage bucket """ if self.client.lookup_bucket(bucket_name): bucket = self.client.get_bucket(bucket_name) else: raise'Bucket not found')'Returning {bucket_name} object') return bucket
[docs] def create_bucket(self, bucket_name): """ Create a bucket. `Args:` bucket_name: str A globally unique name for the bucket. `Returns:` ``None`` """ # To Do: Allow user to set all of the bucket parameters self.client.create_bucket(bucket_name)'Created {bucket_name} bucket.')
[docs] def delete_bucket(self, bucket_name, delete_blobs=False): """ Delete a bucket. Will fail if not empty unless ``delete_blobs`` argument is set to ``True``. `Args:` bucket_name: str The name of the bucket delete_blobs: boolean Delete blobs in the bucket, if it is not empty `Returns:` ``None`` """ bucket = self.get_bucket(bucket_name) bucket.delete(force=delete_blobs)'{bucket_name} bucket deleted.')
[docs] def list_blobs(self, bucket_name, max_results=None, prefix=None): """ List all of the blobs in a bucket `Args:` bucket_name: str The name of the bucket max_results: int TBD prefix_filter: str A prefix to filter files `Returns:` A list of blob names """ blobs = self.client.list_blobs(bucket_name, max_results=max_results, prefix=prefix) lst = [ for b in blobs]'Found {len(lst)} in {bucket_name} bucket.') return lst
[docs] def blob_exists(self, bucket_name, blob_name): """ Verify that a blob exists in the specified bucket `Args:` bucket_name: str The bucket name blob_name: str The name of the blob `Returns:` boolean """ if blob_name in self.list_blobs(bucket_name):'{blob_name} exists.') return True else:'{blob_name} does not exist.') return False
[docs] def get_blob(self, bucket_name, blob_name): """ Get a blob object `Args: bucket_name: str A bucket name blob_name: str A blob name `Returns:` A Google Storage blob object """ bucket = self.get_bucket(bucket_name) blob = bucket.get_blob(blob_name) logger.debug(f'Got {blob_name} object from {bucket_name} bucket.') return blob
[docs] def put_blob(self, bucket_name, blob_name, local_path): """ Puts a blob (aka file) in a bucket `Args:` blob_name: The name of blob to be stored in the bucket bucket_name: The name of the bucket to store the blob local_path: str The local path of the file to upload `Returns:` ``None`` """ bucket = self.get_bucket(bucket_name) blob = storage.Blob(blob_name, bucket) with open(local_path, "rb") as f: blob.upload_from_file(f)'{blob_name} put in {bucket_name} bucket.')
[docs] def download_blob(self, bucket_name, blob_name, local_path=None): """ Gets a blob from a bucket `Args:` bucket_name: str The name of the bucket blob_name: str The name of the blob local_path: str The local path where the file will be downloaded. If not specified, a temporary file will be created and returned, and that file will be removed automatically when the script is done running. `Returns:` str The path of the downloaded file """ if not local_path: local_path = files.create_temp_file_for_path('TEMPTHING') bucket = storage.Bucket(self.client, name=bucket_name) blob = storage.Blob(blob_name, bucket)'Downloading {blob_name} from {bucket_name} bucket.') with open(local_path, 'wb') as f: blob.download_to_file(f, client=self.client)'{blob_name} saved to {local_path}.') return local_path
[docs] def delete_blob(self, bucket_name, blob_name): """ Delete a blob `Args:` bucket_name: str The bucket name blob_name: str The blob name `Returns:` ``None`` """ blob = self.get_blob(bucket_name, blob_name) blob.delete()'{blob_name} blob in {bucket_name} bucket deleted.')
[docs] def upload_table(self, table, bucket_name, blob_name, data_type='csv', default_acl=None): """ Load the data from a Parsons table into a blob. `Args:` table: obj A :ref:`parsons-table` bucket_name: str The name of the bucket to upload the data into. blob_name: str The name of the blob to upload the data into. data_type: str The file format to use when writing the data. One of: `csv` or `json` """ bucket = storage.Bucket(self.client, name=bucket_name) blob = storage.Blob(blob_name, bucket) if data_type == 'csv': local_file = table.to_csv() content_type = 'text/csv' elif data_type == 'json': local_file = table.to_json() content_type = 'application/json' else: raise ValueError(f'Unknown data_type value ({data_type}): must be one of: csv or json') try: blob.upload_from_filename(local_file, content_type=content_type, client=self.client, predefined_acl=default_acl) finally: files.close_temp_file(local_file) return f'gs://{bucket_name}/{blob_name}'