dbt-selly/dbt-env/lib/python3.8/site-packages/agate/tableset/merge.py

52 lines
1.8 KiB
Python

#!/usr/bin/env python
# pylint: disable=W0212
from agate.rows import Row
from agate.tableset import Table
def merge(self, groups=None, group_name=None, group_type=None):
"""
Convert this TableSet into a single table. This is the inverse of
:meth:`.Table.group_by`.
Any `row_names` set on the merged tables will be lost in this
process.
:param groups:
A list of grouping factors to add to merged rows in a new column.
If specified, it should have exactly one element per :class:`Table`
in the :class:`TableSet`. If not specified or None, the grouping
factor will be the name of the :class:`Row`'s original Table.
:param group_name:
This will be the column name of the grouping factors. If None,
defaults to the :attr:`TableSet.key_name`.
:param group_type:
This will be the column type of the grouping factors. If None,
defaults to the :attr:`TableSet.key_type`.
:returns:
A new :class:`Table`.
"""
if type(groups) is not list and groups is not None:
raise ValueError('Groups must be None or a list.')
if type(groups) is list and len(groups) != len(self):
raise ValueError('Groups length must be equal to TableSet length.')
column_names = list(self._column_names)
column_types = list(self._column_types)
column_names.insert(0, group_name if group_name else self._key_name)
column_types.insert(0, group_type if group_type else self._key_type)
rows = []
for index, (key, table) in enumerate(self.items()):
for row in table._rows:
if groups is None:
rows.append(Row((key,) + tuple(row), column_names))
else:
rows.append(Row((groups[index],) + tuple(row), column_names))
return Table(rows, column_names, column_types)