diff --git a/pint/facets/numpy/numpy_func.py b/pint/facets/numpy/numpy_func.py
index 8b95fb322..2ba2a663a 100644
--- a/pint/facets/numpy/numpy_func.py
+++ b/pint/facets/numpy/numpy_func.py
@@ -1011,9 +1011,7 @@ def implementation(a, *args, **kwargs):
     "linalg.norm",
 ):
     implement_func("function", func_str, input_units=None, output_unit="sum")
-for func_str in ("diff", "ediff1d",
-    "std",
-    "nanstd",):
+for func_str in ("diff", "ediff1d", "std", "nanstd"):
     implement_func("function", func_str, input_units=None, output_unit="delta")
 for func_str in ("gradient",):
     implement_func("function", func_str, input_units=None, output_unit="delta,div")
diff --git a/pint/testsuite/test_numpy.py b/pint/testsuite/test_numpy.py
index e4059ccf4..fbe506c26 100644
--- a/pint/testsuite/test_numpy.py
+++ b/pint/testsuite/test_numpy.py
@@ -858,7 +858,6 @@ def test_var_numpy_func(self):
         assert np.var(self.q) == 1.25 * self.ureg.m**2
         assert np.var(self.q_temperature) == 1.25 * self.ureg.delta_degC**2
 
-
     @helpers.requires_array_function_protocol()
     def test_nanvar_numpy_func(self):
         helpers.assert_quantity_almost_equal(
@@ -879,7 +878,7 @@ def test_std_numpy_func(self):
             np.std(self.q), 1.11803 * self.ureg.m, rtol=1e-5
         )
         helpers.assert_quantity_almost_equal(
-            np.std(self.q_temperature) , 1.11803 * self.ureg.delta_degC, rtol=1e-5
+            np.std(self.q_temperature), 1.11803 * self.ureg.delta_degC, rtol=1e-5
         )
 
     def test_cumprod(self):