more checking, docstring formatting

CHANGELOG.md

@@ -12,6 +12,8 @@ SPDX-License-Identifier: GPL-3.0-or-later
 - added checks and unified error message for common inputs.
 ### Changed
 - pin pandas to versions >= 2.0
+- parameter `fill_na` of `SaQC.flagUniLOF` and `SaQC.assignUniLOF` is now of type 
+  `bool` instead of one of `[None, "linear"]`
 ### Removed
 - removed deprecated `DictOfSeries.to_df`
 ### Fixed

saqc/funcs/scores.py

@@ -405,7 +405,7 @@ class ScoresMixin:
         algorithm: Literal["ball_tree", "kd_tree", "brute", "auto"] = "ball_tree",
         p: int = 1,
         density: Literal["auto"] | float | Callable = "auto",
-        fill_na: str = "linear",
+        fill_na: bool = True,
         **kwargs,
     ) -> "SaQC":
         """
@@ -449,7 +449,7 @@ class ScoresMixin:
               (passed as Series).
 
         fill_na :
-            Weather or not to fill NaN values in the data with a linear interpolation.
+            If True, NaNs in the data are filled with a linear interpolation.
 
         Notes
         -----
@@ -465,8 +465,8 @@ class ScoresMixin:
         """
 
         vals = self._data[field]
-        if fill_na is not None:
-            vals = vals.interpolate(fill_na)
+        if fill_na:
+            vals = vals.interpolate('linear')
 
         if density == "auto":
             density = vals.diff().abs().median()

saqc/lib/checking.py

@@ -31,6 +31,10 @@ def isBoolLike(obj: Any, optional: bool = False) -> bool:
     )
 
 
+def isFloatLike(obj: Any) -> bool:
+    return isinstance(obj, (float, int))
+
+
 def isIterable(obj: Any) -> bool:
     if isinstance(obj, Iterable) or pd.api.types.is_iterator(obj):
         return True

saqc/lib/tools.py

@@ -26,6 +26,7 @@ from typing import (
     Union,
     get_args,
     get_origin,
+    overload,
 )
 
 import numpy as np
@@ -57,12 +58,18 @@ def assertScalar(name, value, optional=False):
     return validateScalar(name=name, value=value, optional=optional)
 
 
-def toSequence(value: T | Sequence[T]) -> List[T]:
-    if value is None:  # special case
-        return [None]
-    if isinstance(value, (str, float, int)):
+# fmt: off
+@overload
+def toSequence(value: T) -> List[T]:
+    ...
+@overload
+def toSequence(value: Sequence[T]) -> List[T]:
+    ...
+def toSequence(value) -> List:
+    if value is None or isinstance(value, (str, float, int)):
         return [value]
     return list(value)
+# fmt: on
 
 
 def squeezeSequence(value: Sequence[T]) -> Union[T, Sequence[T]]: