def _columns_filter_helper(columns):
"""Creates a union filter for a list of columns.
:type columns: list
:param columns: Iterable containing column names (as strings). Each column
name can be either
* an entire column family: ``fam`` or ``fam:``
* an single column: ``fam:col``
:rtype: :class:`.RowFilterUnion`, :class:`.RowFilter`
:returns: The union filter created containing all of the matched columns.
:raises: :class:`ValueError <exceptions.ValueError>` if there are no
filters to union.
"""
filters = []
for column_family_id, column_qualifier in _get_column_pairs(columns):
if column_qualifier is not None:
fam_filter = RowFilter(family_name_regex_filter=column_family_id)
qual_filter = RowFilter(
column_qualifier_regex_filter=column_qualifier)
combined_filter = RowFilterChain(
filters=[fam_filter, qual_filter])
filters.append(combined_filter)
else:
fam_filter = RowFilter(family_name_regex_filter=column_family_id)
filters.append(fam_filter)
num_filters = len(filters)
if num_filters == 0:
raise ValueError('Must have at least one filter.')
elif num_filters == 1:
return filters[0]
else:
return RowFilterUnion(filters=filters)
def _callFUT(self, *args, **kwargs):
from gcloud_bigtable.happybase.batch import _get_column_pairs
return _get_column_pairs(*args, **kwargs)
