Merge branch 'develop' into 'multifields'

# Conflicts:
#   saqc/core/core.py

saqc/core/core.py

@@ -244,7 +244,7 @@ class SaQC(FunctionsMixin):
             # expand regular expressions
             if regex:
                 fmask = self._data.columns.str.match(field)
-                fields: list = self._data.columns[fmask].tolist()
+                fields = self._data.columns[fmask].tolist()
             else:
                 fields = toSequence(field)
 
@@ -252,6 +252,7 @@ class SaQC(FunctionsMixin):
                 # we wrap field again to generalize the down stream loop work as expected
                 fields = [fields]
 
+
             out = self
 
             for f in fields: