typing toSequence is hard...

saqc/core/core.py

@@ -218,7 +218,7 @@ class SaQC(FunctionsMixin):
         """
 
         def inner(
-            field: str,
+            field: str | Sequence[str],
             *args,
             regex: bool = False,
             flag: ExternalFlag = None,
@@ -233,25 +233,23 @@ class SaQC(FunctionsMixin):
 
             # expand regular expressions
             if regex:
-                fields = self._data.columns.str.match(field)
-                fields = self._data.columns[fields]
+                fmask = self._data.columns.str.match(field)
+                fields: list = self._data.columns[fmask].tolist()
             else:
                 fields = toSequence(field)
 
             if func.__multivariate__:
-                # we wrap field again to make the downstream loop work as expected
-                fields = [
-                    fields,
-                ]
+                # we wrap field again to generalize the down stream loop work as expected
+                fields = [fields]
 
             out = self
 
-            for field in fields:
+            for f in fields:
                 out = out._callFunction(
                     func,
                     data=out._data,
                     flags=out._flags,
-                    field=field,
+                    field=f,
                     *args,
                     **kwargs,
                 )
@@ -264,7 +262,7 @@ class SaQC(FunctionsMixin):
         function: Callable,
         data: DictOfSeries,
         flags: Flags,
-        field: str,
+        field: str | Sequence[str],
         *args: Any,
         **kwargs: Any,
     ) -> SaQC:

saqc/lib/tools.py

 #! /usr/bin/env python
 # -*- coding: utf-8 -*-
+from __future__ import annotations
 
 import re
 import datetime
 import itertools
 import warnings
-from typing import List, Sequence, Union, Any, Iterator, Callable
+from typing import List, Sequence, TypeVar, Union, Any, Iterator, Callable
 
 import numpy as np
 import numba as nb
@@ -16,13 +17,14 @@ import dios
 import collections
 from scipy.cluster.hierarchy import linkage, fcluster
 
-from saqc.lib.types import T
-
 # keep this for external imports
 # TODO: fix the external imports
 from saqc.lib.rolling import customRoller
 
 
+T = TypeVar("T", str, float, int)
+
+
 def assertScalar(name, value, optional=False):
     if (not np.isscalar(value)) and (value is not None) and (optional is True):
         raise ValueError(f"'{name}' needs to be a scalar or 'None'")
@@ -30,9 +32,9 @@ def assertScalar(name, value, optional=False):
         raise ValueError(f"'{name}' needs to be a scalar")
 
 
-def toSequence(value: Union[Any, Sequence[Any]]) -> List[Any]:
-    if np.isscalar(value):
-        value = [value]
+def toSequence(value: T | Sequence[T]) -> List[T]:
+    if isinstance(value, (str, int, float)):
+        return [value]
     return list(value)