[pre-commit.ci] auto fixes from pre-commit.com hooks

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Python/pywarpx/picmi.py

@@ -754,9 +754,7 @@ def distribution_initialize_inputs(
         if density_scale is not None:
             species.add_new_group_attr(source_name, "flux", density_scale)
 
-        expression = pywarpx.my_constants.mangle_expression(
-            self.flux, self.mangle_dict
-        )
+        expression = pywarpx.my_constants.mangle_expression(self.flux, self.mangle_dict)
         if density_scale is None:
             species.add_new_group_attr(
                 source_name, "flux_function(x,y,z,t)", expression
@@ -768,7 +766,6 @@ def distribution_initialize_inputs(
                 "{}*({})".format(density_scale, expression),
             )
 
-
         species.add_new_group_attr(
             source_name, "flux_normal_axis", self.flux_normal_axis
         )