diff --git a/saqc/funcs/flagtools.py b/saqc/funcs/flagtools.py
index 5b9c3c646a7d05dcab7c083446fd8c4cf14aac83..3ec5d839cb1e8f3b7f564931b3954a103d380454 100644
--- a/saqc/funcs/flagtools.py
+++ b/saqc/funcs/flagtools.py
@@ -20,7 +20,13 @@ from saqc.core import DictOfSeries, flagging, register
 from saqc.core.flags import Flags
 from saqc.core.history import History
 from saqc.lib.checking import validateChoice, validateWindow
-from saqc.lib.tools import initializeTargets, isflagged, isunflagged, multivariateParameters, toSequence
+from saqc.lib.tools import (
+    initializeTargets,
+    isflagged,
+    isunflagged,
+    multivariateParameters,
+    toSequence,
+)
 
 if TYPE_CHECKING:
     from saqc import SaQC
@@ -365,9 +371,7 @@ class FlagtoolsMixin:
             },
         }
 
-
         for field, target in zip(fields, targets):
-
             # initialize non existing targets
             if target not in self._data:
                 self._data[target] = pd.Series(np.nan, index=self._data[field].index)
@@ -403,7 +407,6 @@ class FlagtoolsMixin:
 
         return self
 
-
     @flagging()
     def propagateFlags(
         self: "SaQC",
diff --git a/tests/funcs/test_flagtools.py b/tests/funcs/test_flagtools.py
index efadb021948056f0b860d9b997fd9edb734a4481..eb4081bdf5750b20b29412d9d67a5900c298be0f 100644
--- a/tests/funcs/test_flagtools.py
+++ b/tests/funcs/test_flagtools.py
@@ -218,6 +218,3 @@ def test_transferFlags():
     assert qc3._history["a"].hist.iloc[:, 0].equals(qc3._history["x"].hist.squeeze())
     assert qc3._history["a"].hist.iloc[:, 1].equals(qc3._history["y"].hist.squeeze())
     assert qc3._history["a"].hist.iloc[:, 2].equals(qc3._history["z"].hist.squeeze())
-
-
-