[AIRFLOW-315] Fix blank lines code style warnings

Closes apache#1653 from skudriashev/airflow-315

airflow/bin/cli.py

@@ -1026,5 +1026,6 @@ def get_parser(cls, dag_parser=False):
             sp.set_defaults(func=sub['func'])
         return parser
 
+
 def get_parser():
     return CLIFactory.get_parser()

airflow/configuration.py

@@ -37,6 +37,7 @@
 warnings.filterwarnings(
     action='default', category=PendingDeprecationWarning, module='airflow')
 
+
 class AirflowConfigException(Exception):
     pass
 

airflow/contrib/auth/backends/github_enterprise_auth.py

@@ -31,6 +31,7 @@
 
 _log = logging.getLogger(__name__)
 
+
 def get_config_param(param):
     return str(configuration.get('github_enterprise', param))
 

airflow/contrib/auth/backends/ldap_auth.py

@@ -44,6 +44,7 @@
 class AuthenticationError(Exception):
     pass
 
+
 class LdapException(Exception):
     pass
 

airflow/contrib/auth/backends/password_auth.py

@@ -43,6 +43,7 @@
 LOG = logging.getLogger(__name__)
 PY3 = version_info[0] == 3
 
+
 class AuthenticationError(Exception):
     pass
 

airflow/contrib/hooks/datastore_hook.py

@@ -16,6 +16,7 @@
 from apiclient.discovery import build
 from airflow.contrib.hooks.gcp_api_base_hook import GoogleCloudBaseHook
 
+
 class DatastoreHook(GoogleCloudBaseHook):
     """
     Interact with Google Cloud Datastore. This hook uses the Google Cloud Platform

airflow/contrib/hooks/qubole_hook.py

@@ -56,6 +56,7 @@
     'dbimportcmd': ['mode', 'hive_table', 'dbtap_id', 'db_table', 'where_clause', 'parallelism', 'extract_query', 'boundary_query', 'split_column', 'tags', 'name']
 }
 
+
 class QuboleHook(BaseHook):
     def __init__(self, *args, **kwargs):
         conn = self.get_connection(kwargs['qubole_conn_id'])

airflow/contrib/hooks/vertica_hook.py

@@ -17,6 +17,7 @@
 
 from airflow.hooks.dbapi_hook import DbApiHook
 
+
 class VerticaHook(DbApiHook):
     '''
     Interact with Vertica.

airflow/contrib/operators/bigquery_operator.py

@@ -18,6 +18,7 @@
 from airflow.models import BaseOperator
 from airflow.utils.decorators import apply_defaults
 
+
 class BigQueryOperator(BaseOperator):
     """
     Executes BigQuery SQL queries in a specific BigQuery database

airflow/contrib/operators/bigquery_to_bigquery.py

@@ -18,6 +18,7 @@
 from airflow.models import BaseOperator
 from airflow.utils.decorators import apply_defaults
 
+
 class BigQueryToBigQueryOperator(BaseOperator):
     """
     Copy a BigQuery table to another BigQuery table.

airflow/contrib/operators/bigquery_to_gcs.py

@@ -18,6 +18,7 @@
 from airflow.models import BaseOperator
 from airflow.utils.decorators import apply_defaults
 
+
 class BigQueryToCloudStorageOperator(BaseOperator):
     """
     Transfers a BigQuery table to a Google Cloud Storage bucket.

airflow/contrib/operators/fs_operator.py

@@ -20,6 +20,7 @@
 from airflow.contrib.hooks.fs_hook import FSHook
 from airflow.utils.decorators import apply_defaults
 
+
 class FileSensor(BaseSensorOperator):
     """
     Waits for a file or folder to land in a filesystem

airflow/contrib/operators/gcs_download_operator.py

@@ -19,6 +19,7 @@
 from airflow.models import BaseOperator
 from airflow.utils.decorators import apply_defaults
 
+
 class GoogleCloudStorageDownloadOperator(BaseOperator):
     """
     Downloads a file from Google Cloud Storage.

airflow/contrib/operators/gcs_to_bq.py

@@ -20,6 +20,7 @@
 from airflow.models import BaseOperator
 from airflow.utils.decorators import apply_defaults
 
+
 class GoogleCloudStorageToBigQueryOperator(BaseOperator):
     """
     Loads files from Google cloud storage into BigQuery.

airflow/contrib/operators/mysql_to_gcs.py

@@ -26,6 +26,7 @@
 from MySQLdb.constants import FIELD_TYPE
 from tempfile import NamedTemporaryFile
 
+
 class MySqlToGoogleCloudStorageOperator(BaseOperator):
     """
     Copy data from MySQL to Google cloud storage in JSON format.

airflow/contrib/operators/vertica_to_hive.py

@@ -23,6 +23,7 @@
 from airflow.models import BaseOperator
 from airflow.utils.decorators import apply_defaults
 
+
 class VerticaToHiveTransfer(BaseOperator):
     """
     Moves data from Vertia to Hive. The operator runs

airflow/example_dags/example_branch_python_dop_operator_3.py

@@ -31,6 +31,7 @@
 # alternating runs
 dag = DAG(dag_id='example_branch_dop_operator_v3',schedule_interval='*/1 * * * *',  default_args=args)
 
+
 def should_run(ds, **kwargs):
 
     print("------------- exec dttm = {} and minute = {}".format(kwargs['execution_date'], kwargs['execution_date'].minute))

airflow/example_dags/example_passing_params_via_test_command.py

@@ -26,6 +26,7 @@
           dagrun_timeout=timedelta(minutes=4)
           )
 
+
 def my_py_command(ds, **kwargs):
     # Print out the "foo" param passed in via
     # `airflow test example_passing_params_via_test_command run_this <date>

airflow/example_dags/example_xcom.py

@@ -33,14 +33,17 @@
 value_1 = [1, 2, 3]
 value_2 = {'a': 'b'}
 
+
 def push(**kwargs):
     # pushes an XCom without a specific target
     kwargs['ti'].xcom_push(key='value from pusher 1', value=value_1)
 
+
 def push_by_returning(**kwargs):
     # pushes an XCom without a specific target, just by returning it
     return value_2
 
+
 def puller(**kwargs):
     ti = kwargs['ti']
 

airflow/exceptions.py

@@ -12,9 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
-#
-# Any AirflowException raised is expected to cause the TaskInstance to be marked in an ERROR state
-#
+# Note: Any AirflowException raised is expected to cause the TaskInstance
+#       to be marked in an ERROR state
+
+
 class AirflowException(Exception):
     pass
 
@@ -27,9 +28,5 @@ class AirflowTaskTimeout(AirflowException):
     pass
 
 
-#
-# Any AirflowSkipException raised is expected to cause the TaskInstance to be marked in an SKIPPED state
-#
 class AirflowSkipException(AirflowException):
     pass
-

airflow/hooks/__init__.py

@@ -61,6 +61,7 @@
     from airflow.utils.helpers import AirflowImporter
     airflow_importer = AirflowImporter(sys.modules[__name__], _hooks)
 
+
 def _integrate_plugins():
     """Integrate plugins to the context"""
     import sys

airflow/hooks/druid_hook.py

@@ -26,6 +26,7 @@
 LOAD_CHECK_INTERVAL = 5
 DEFAULT_TARGET_PARTITION_SIZE = 5000000
 
+
 class AirflowDruidLoadException(AirflowException):
     pass
 

airflow/hooks/mysql_hook.py

@@ -17,6 +17,7 @@
 
 from airflow.hooks.dbapi_hook import DbApiHook
 
+
 class MySqlHook(DbApiHook):
     '''
     Interact with MySQL.

airflow/migrations/versions/13eb55f81627_for_compatibility.py

@@ -26,8 +26,10 @@
 branch_labels = None
 depends_on = None
 
+
 def upgrade():
     pass
 
+
 def downgrade():
-    pass
+    pass

airflow/migrations/versions/211e584da130_add_ti_state_index.py

@@ -33,5 +33,6 @@
 def upgrade():
     op.create_index('ti_state', 'task_instance', ['state'], unique=False)
 
+
 def downgrade():
     op.drop_index('ti_state', table_name='task_instance')

airflow/migrations/versions/338e90f54d61_more_logging_into_task_isntance.py

@@ -30,6 +30,7 @@
 import sqlalchemy as sa
 from sqlalchemy.dialects import mysql
 
+
 def upgrade():
     ### commands auto generated by Alembic - please adjust! ###
     op.add_column('task_instance', sa.Column('operator', sa.String(length=1000), nullable=True))

airflow/migrations/versions/4446e08588_dagrun_start_end.py

@@ -29,6 +29,7 @@
 from alembic import op
 import sqlalchemy as sa
 
+
 def upgrade():
     op.add_column('dag_run', sa.Column('end_date', sa.DateTime(), nullable=True))
     op.add_column('dag_run', sa.Column('start_date', sa.DateTime(), nullable=True))

airflow/operators/__init__.py

@@ -97,6 +97,7 @@
     from airflow.utils.helpers import AirflowImporter
     airflow_importer = AirflowImporter(sys.modules[__name__], _operators)
 
+
 def _integrate_plugins():
     """Integrate plugins to the context"""
     import sys

airflow/operators/hive_to_mysql.py

@@ -21,6 +21,7 @@
 
 from tempfile import NamedTemporaryFile
 
+
 class HiveToMySqlTransfer(BaseOperator):
     """
     Moves data from Hive to MySQL, note that for now the data is loaded

airflow/plugins_manager.py

@@ -29,9 +29,11 @@
 
 from airflow import configuration
 
+
 class AirflowPluginException(Exception):
     pass
 
+
 class AirflowPlugin(object):
     name = None
     operators = []
@@ -89,6 +91,7 @@ def validate(cls):
             logging.exception(e)
             logging.error('Failed to import plugin ' + filepath)
 
+
 def make_module(name, objects):
     name = name.lower()
     module = imp.new_module(name)

airflow/security/kerberos.py

@@ -101,6 +101,7 @@ def detect_conf_var():
     finally:
         f.close()
 
+
 def run():
     if configuration.get('kerberos','keytab') is None:
         LOG.debug("Keytab renewer not starting, no keytab configured")

airflow/security/utils.py

@@ -71,6 +71,7 @@ def get_fqdn(hostname_or_ip=None):
 
     return fqdn
 
+
 def principal_from_username(username):
     realm = conf.get("security", "default_realm")
     if '@' not in username and realm:

airflow/utils/helpers.py

@@ -74,6 +74,7 @@ def ask_yesno(question):
         else:
             print("Please respond by yes or no.")
 
+
 def is_in(obj, l):
     """
     Checks whether an object is one of the item in the list.

airflow/utils/logging.py

@@ -24,6 +24,7 @@
 from airflow import configuration
 from airflow.exceptions import AirflowException
 
+
 class LoggingMixin(object):
     """
     Convenience super-class to have a logger configured with the class name
@@ -80,7 +81,6 @@ def read(self, remote_log_location, return_error=False):
         logging.error(err)
         return err if return_error else ''
 
-
     def write(self, log, remote_log_location, append=False):
         """
         Writes the log to the remote_log_location. Fails silently if no hook

airflow/www/app.py

@@ -127,6 +127,8 @@ def shutdown_session(exception=None):
         return app
 
 app = None
+
+
 def cached_app(config=None):
     global app
     if not app:

airflow/www/utils.py

@@ -185,6 +185,7 @@ def json_response(obj):
         status=200,
         mimetype="application/json")
 
+
 def gzipped(f):
     '''
     Decorator to make a view compressed

airflow/www/views.py

@@ -1795,6 +1795,7 @@ class SlaMissModelView(wwwutils.SuperUserMixin, ModelViewOnly):
         'timestamp': {'disabled': True},
     }
 
+
 class ChartModelView(wwwutils.DataProfilingMixin, AirflowModelView):
     verbose_name = "chart"
     verbose_name_plural = "charts"