target broadcasting and numpy array support for generics

adresses #468 (closed)

• added target broadcasting for generics
• added support for numpy arrays as generic function return when those match the target frame in shape

-> i noted in the changelog.md there was already an entry stating broadcasting support was added already for flagGeneric: i didnt get into that, but a simple flagGeneric('v', func=lambda x: True) threw an exception complaining return type wasnt a series -> so didnt really work for the use case

saqc/funcs/generic.py

@@ -83,15 +83,17 @@ def _inferBroadcast(obj, trg_shape) -> pd.DataFrame:
         return np.full(trg_shape, obj)
     return obj
 
+
 def _inferDF(obj, cols, index):
     # infer dataframe if result is numpy array of fitting shape
     if isinstance(obj, np.ndarray):
         lc = len(cols)
         li = len(index)
-        if (obj.shape == (li,lc)) or (obj.shape == (li,)):
+        if (obj.shape == (li, lc)) or (obj.shape == (li,)):
             return pd.DataFrame(obj, columns=cols, index=index)
     return obj
 
+
 def _castResult(obj) -> DictOfSeries:
     # Note: the actual keys aka. column names
     # we use here to create a DictOfSeries