Source code for airflow.macros.hive

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import datetime


[docs]def max_partition( table, schema="default", field=None, filter=None, metastore_conn_id='metastore_default'): ''' Gets the max partition for a table. :param schema: The hive schema the table lives in :type schema: string :param table: The hive table you are interested in, supports the dot notation as in "my_database.my_table", if a dot is found, the schema param is disregarded :type table: string :param hive_conn_id: The hive connection you are interested in. If your default is set you don't need to use this parameter. :type hive_conn_id: string :param filter: filter on a subset of partition as in `sub_part='specific_value'` :type filter: string :param field: the field to get the max value from. If there's only one partition field, this will be inferred >>> max_partition('airflow.static_babynames_partitioned') '2015-01-01' ''' from airflow.hooks.hive_hooks import HiveMetastoreHook if '.' in table: schema, table = table.split('.') hh = HiveMetastoreHook(metastore_conn_id=metastore_conn_id) return hh.max_partition( schema=schema, table_name=table, field=field, filter=filter)
def _closest_date(target_dt, date_list, before_target=None): ''' This function finds the date in a list closest to the target date. An optional parameter can be given to get the closest before or after. :param target_dt: The target date :type target_dt: datetime.date :param date_list: The list of dates to search :type date_list: datetime.date list :param before_target: closest before or after the target :type before_target: bool or None :returns: The closest date :rtype: datetime.date or None ''' fb = lambda d: target_dt - d if d <= target_dt else datetime.timedelta.max fa = lambda d: d - target_dt if d >= target_dt else datetime.timedelta.max fnone = lambda d: target_dt - d if d < target_dt else d - target_dt if before_target is None: return min(date_list, key=fnone).date() if before_target: return min(date_list, key=fb).date() else: return min(date_list, key=fa).date()
[docs]def closest_ds_partition( table, ds, before=True, schema="default", metastore_conn_id='metastore_default'): ''' This function finds the date in a list closest to the target date. An optional parameter can be given to get the closest before or after. :param table: A hive table name :type table: str :param ds: A datestamp ``%Y-%m-%d`` e.g. ``yyyy-mm-dd`` :type ds: datetime.date list :param before: closest before (True), after (False) or either side of ds :type before: bool or None :returns: The closest date :rtype: str or None >>> tbl = 'airflow.static_babynames_partitioned' >>> closest_ds_partition(tbl, '2015-01-02') '2015-01-01' ''' from airflow.hooks.hive_hooks import HiveMetastoreHook if '.' in table: schema, table = table.split('.') hh = HiveMetastoreHook(metastore_conn_id=metastore_conn_id) partitions = hh.get_partitions(schema=schema, table_name=table) if not partitions: return None part_vals = [list(p.values())[0] for p in partitions] if ds in part_vals: return ds else: parts = [datetime.datetime.strptime(pv, '%Y-%m-%d') for pv in part_vals] target_dt = datetime.datetime.strptime(ds, '%Y-%m-%d') closest_ds = _closest_date(target_dt, parts, before_target=before) return closest_ds.isoformat()