diff --git a/fv3core/pace/fv3core/initialization/baroclinic.py b/fv3core/pace/fv3core/initialization/baroclinic.py
index ba4e994d..3efe722d 100644
--- a/fv3core/pace/fv3core/initialization/baroclinic.py
+++ b/fv3core/pace/fv3core/initialization/baroclinic.py
@@ -10,7 +10,7 @@
 import pace.util.constants as constants
 from pace.dsl.typing import Float
 from pace.fv3core.initialization.dycore_state import DycoreState
-from pace.util.grid import GridData, lon_lat_midpoint, compute_eta
+from pace.util.grid import GridData, compute_eta, lon_lat_midpoint
 
 
 nhalo = fv3util.N_HALO_DEFAULT
diff --git a/fv3core/pace/fv3core/initialization/baroclinic_jablonowski_williamson.py b/fv3core/pace/fv3core/initialization/baroclinic_jablonowski_williamson.py
index bcf7bd91..dd7dccc3 100644
--- a/fv3core/pace/fv3core/initialization/baroclinic_jablonowski_williamson.py
+++ b/fv3core/pace/fv3core/initialization/baroclinic_jablonowski_williamson.py
@@ -3,7 +3,7 @@
 import numpy as np
 
 import pace.util.constants as constants
-from pace.util.grid import great_circle_distance_lon_lat, vertical_coordinate, compute_eta
+from pace.util.grid import great_circle_distance_lon_lat, vertical_coordinate
 
 
 """
diff --git a/tests/main/grid/__init__.py b/tests/main/grid/__init__.py
index 8b137891..e69de29b 100644
--- a/tests/main/grid/__init__.py
+++ b/tests/main/grid/__init__.py
@@ -1 +0,0 @@
-
diff --git a/tests/main/grid/test_eta.py b/tests/main/grid/test_eta.py
index 3555670d..2939218f 100755
--- a/tests/main/grid/test_eta.py
+++ b/tests/main/grid/test_eta.py
@@ -1,58 +1,58 @@
 #!/usr/bin/env python3
 
-import os
-import pytest
 import numpy as np
+import pytest
+
 from pace.util.grid.eta import set_hybrid_pressure_coefficients
 
+
 km = 79
-eta_file='./input/eta79.txt'
+eta_file = "./input/eta79.txt"
 ak_79, bk_79 = np.loadtxt(eta_file, unpack=True)
 
+
 @pytest.mark.xfail
-def test_set_hybrid_pressure_coefficients_nofile( ) :
+def test_set_hybrid_pressure_coefficients_nofile():
 
     """ File does not exist.  Test should fail """
 
-    pressure_data = set_hybrid_pressure_coefficients( km=90 )
-    
+    pressure_data = set_hybrid_pressure_coefficients(km=90)
 
-def test_set_hybrid_pressure_coefficients_correct( ) :
+
+def test_set_hybrid_pressure_coefficients_correct():
 
     """  Good values of ak, bk.  Test should pass """
 
     ks = 18
     ptop = 300.0
 
-    pressure_data = set_hybrid_pressure_coefficients( km )
-    
-    if( not np.array_equal(ak_79,pressure_data.ak) ) :
+    pressure_data = set_hybrid_pressure_coefficients(km)
+
+    if not np.array_equal(ak_79, pressure_data.ak):
         raise ValueError("Unexpected values in ak array")
 
-    if( not np.array_equal(bk_79,pressure_data.bk) ) :
+    if not np.array_equal(bk_79, pressure_data.bk):
         raise ValueError("Unexpected values in bk array")
 
-    if( ks != pressure_data.ks ) :
+    if ks != pressure_data.ks:
         raise ValueError("Unexpected ks value")
 
-    if( ptop != pressure_data.ptop) :
+    if ptop != pressure_data.ptop:
         raise ValueError("Unexpected ptopt value")
 
-    
+
 @pytest.mark.xfail
-def test_set_hybrid_pressure_coefficients_nonincreasing( ) :
+def test_set_hybrid_pressure_coefficients_nonincreasing():
 
     """
     Array bk is not monotonically increasing.
     Test is expected to fail
     """
 
-    ak_cp = ak_79k[:]
+    ak_cp = ak_79[:]
     bk_cp = bk_79[:]
 
-    bk_cp[10]=0.1 #random number
-    ak_cp[13]=1.4 #random number
-
-    pressure_data = set_hybrid_pressure_coefficients( km )
+    bk_cp[10] = 0.1  # random number
+    ak_cp[13] = 1.4  # random number
 
-    
+    pressure_data = set_hybrid_pressure_coefficients(km)
diff --git a/util/pace/util/grid/__init__.py b/util/pace/util/grid/__init__.py
index db25ef97..2a755d0c 100644
--- a/util/pace/util/grid/__init__.py
+++ b/util/pace/util/grid/__init__.py
@@ -21,9 +21,4 @@
     VerticalGridData,
 )
 from .stretch_transformation import direct_transform
-
-from .utils import (
-    vertical_coordinate,
-    compute_eta,
-)
-    
+from .utils import compute_eta, vertical_coordinate
diff --git a/util/pace/util/grid/eta.py b/util/pace/util/grid/eta.py
index 13aaed9f..4589e943 100644
--- a/util/pace/util/grid/eta.py
+++ b/util/pace/util/grid/eta.py
@@ -1,8 +1,10 @@
+import os
 from dataclasses import dataclass
 
-from .utils import compute_eta
 import numpy as np
-import os
+
+from .utils import compute_eta
+
 
 @dataclass
 class HybridPressureCoefficients:
@@ -38,27 +40,32 @@ def set_hybrid_pressure_coefficients(km: int) -> HybridPressureCoefficients:
     """
 
     # set path where the eta file lives
-    GRID_DIR=os.path.join( os.path.abspath('./'), "input/")
+    GRID_DIR = os.path.join(os.path.abspath("./"), "input/")
 
     # set filename, e.g, eta79.txt for km=79
-    eta_file = GRID_DIR + 'eta' + str(km) + '.txt'
-    if( not os.path.isfile(eta_file) ) : raise IOError("file "+eta_file+" does not exist")
+    eta_file = GRID_DIR + "eta" + str(km) + ".txt"
+    if not os.path.isfile(eta_file):
+        raise IOError("file " + eta_file + " does not exist")
 
     # read file into ak, bk arrays
     ak, bk = np.loadtxt(eta_file, unpack=True)
 
     # check size of ak and bk array is km+1
-    if ak.size-1 != km : raise ValueError("size of ak array is not equal to km="+str(km))
-    if bk.size-1 != km : raise ValueError("size of bk array is not equal to km="+str(km))
+    if ak.size - 1 != km:
+        raise ValueError("size of ak array is not equal to km=" + str(km))
+    if bk.size - 1 != km:
+        raise ValueError("size of bk array is not equal to km=" + str(km))
 
     # check that the eta values computed from ak and bk are monotonically increasing
     eta, etav = compute_eta(ak, bk)
 
-    ( eta_sorted, etav_sorted ) = ( np.sort(eta), np.sort(etav) )
-    for i in range( eta.size ) :
-        if eta_sorted[i]  != eta[i]  : raise ValueError("ETA values are not monotonically increasing")
-        if etav_sorted[i] != etav[i] : raise ValueError("ETAV values are not monotonically increasing")
-        
+    (eta_sorted, etav_sorted) = (np.sort(eta), np.sort(etav))
+    for i in range(eta.size):
+        if eta_sorted[i] != eta[i]:
+            raise ValueError("ETA values are not monotonically increasing")
+        if etav_sorted[i] != etav[i]:
+            raise ValueError("ETAV values are not monotonically increasing")
+
     if 0.0 in bk:
         ks = 0 if km == 91 else np.where(bk == 0)[0][-1]
         ptop = ak[0]
@@ -66,5 +73,5 @@ def set_hybrid_pressure_coefficients(km: int) -> HybridPressureCoefficients:
         raise ValueError("bk must contain at least one 0.")
 
     pressure_data = HybridPressureCoefficients(ks, ptop, ak, bk)
-    
+
     return pressure_data
diff --git a/util/pace/util/grid/utils.py b/util/pace/util/grid/utils.py
index ad4837b4..17a15568 100644
--- a/util/pace/util/grid/utils.py
+++ b/util/pace/util/grid/utils.py
@@ -1,10 +1,10 @@
 import math
 
-import numpy as np
 
 eta_0 = 0.252
 surface_pressure = 1.0e5  # units of (Pa), from Table VI of DCMIP2016
 
+
 def vertical_coordinate(eta_value):
     """
     Equation (1) JRMS2006
@@ -21,5 +21,3 @@ def compute_eta(ak, bk):
     eta = 0.5 * ((ak[:-1] + ak[1:]) / surface_pressure + bk[:-1] + bk[1:])
     eta_v = vertical_coordinate(eta)
     return eta, eta_v
-
-