allow target broadcasting in flagGeneric

CHANGELOG.md

@@ -8,6 +8,7 @@ SPDX-License-Identifier: GPL-3.0-or-later
 ## Unreleased
 [List of commits](https://git.ufz.de/rdm-software/saqc/-/compare/v2.5.0...develop)
 ### Added
+- `flagGeneric`: target broadcasting
 ### Changed
 ### Removed
 ### Fixed

saqc/core/translation/basescheme.py

@@ -11,10 +11,9 @@ from __future__ import annotations
 from abc import abstractmethod
 from typing import Any, Dict
 
-import numpy as np
 import pandas as pd
 
-from saqc import BAD, FILTER_ALL, GOOD, UNFLAGGED
+from saqc import BAD, FILTER_ALL, UNFLAGGED
 from saqc.core import DictOfSeries, Flags
 from saqc.lib.types import ExternalFlag
 

saqc/funcs/generic.py

@@ -233,7 +233,7 @@ class GenericMixin:
         result = _execGeneric(fchunk, dchunk, func, dfilter=dfilter)
         result = _castResult(result)
 
-        if len(targets) != len(result.columns):
+        if len(result.columns) > 1 and len(targets) != len(result.columns):
             raise ValueError(
                 f"the generic function returned {len(result.columns)} field(s), "
                 f"but {len(targets)} target(s) were given"
@@ -244,7 +244,8 @@ class GenericMixin:
 
         # update flags & data
         for i, col in enumerate(targets):
-            mask = result[result.columns[i]]
+            # broadcast one column results to all targets
+            mask = result[result.columns[i if len(result.columns) > 1 else 0]]
 
             # make sure the column exists
             if col not in self._flags:

tests/funcs/test_generic_api_functions.py

@@ -41,6 +41,7 @@ def test_emptyData():
             ["tmp1", "tmp2"],
             lambda x, y: [pd.Series(True, index=x.index.union(y.index))] * 2,
         ),
+        (["tmp1", "tmp2"], lambda x, y: pd.Series(True, index=x.index.union(y.index))),
     ],
 )
 def test_writeTargetFlagGeneric(data, targets, func):