a few simplifications

saqc/dsl/evaluator.py

@@ -46,12 +46,6 @@ def initFunctionNamespace(nodata, flagger):
     }
 
 
-def setKey(d, key, value):
-    out = copy.copy(d)
-    out[key] = value
-    return out
-
-
 def _raiseNameError(name, expr):
     raise NameError(
         "name '{:}' is not definied (failing expression: '{:}')"
@@ -63,8 +57,6 @@ def evalExpression(expr: str, flagger: BaseFlagger,
                    field: str, nodata: Number = np.nan,
                    **namespace: dict) -> np.ndarray:
 
-    # type: (...) -> np.ndarray[bool]
-
     def _eval(node, namespace):
         # type: (ast.Node, dict) -> None
         # the namespace dictionary should provide the data frame for the device
@@ -97,8 +89,7 @@ def evalExpression(expr: str, flagger: BaseFlagger,
             except KeyError:
                 _raiseNameError(node.func.id, expr)
 
-            namespace = setKey(namespace, "target", target)
-            args = [_eval(n, namespace) for n in node.args]
+            args = [_eval(n, {**namespace, **{"target": target}}) for n in node.args]
             return func(*args)
 
         elif isinstance(node, ast.Name):  # <variable>

test/flagger/test_baseflagger.py

@@ -29,9 +29,7 @@ def test_accesors():
 def test_isFlagged():
     flagger = BaseFlagger([-1, 0, 1])
     data = initData(cols=1).iloc[:50]
-    flags = pd.DataFrame(index=data.index,
-                         columns=data.columns,
-                         data=flagger.UNFLAGGED)
+    flags = flagger.initFlags(data)
     flags.iloc[:10] = flagger.BAD
     flags.iloc[10:20] = flagger.GOOD