diff --git a/SimPEG/PF/Gravity.py b/SimPEG/PF/Gravity.py
index 79c17252..f4107779 100644
--- a/SimPEG/PF/Gravity.py
+++ b/SimPEG/PF/Gravity.py
@@ -238,13 +238,12 @@ def writeUBCobs(filename, survey, d):
 
     wd = survey.std
 
-    data = np.c_[rxLoc , d , wd]
+    data = np.c_[rxLoc, d, wd]
 
-    with file(filename,'w') as fid:
-        fid.write('%i\n' %len(d) )
+    with file(filename, 'w') as fid:
+        fid.write('%i\n' % len(d))
         np.savetxt(fid, data, fmt='%e', delimiter=' ', newline='\n')
 
-
     print "Observation file saved to: " + filename
 
 
diff --git a/tests/mesh/test_MeshIO.py b/tests/mesh/test_MeshIO.py
index e8dc0748..2eea5cbf 100644
--- a/tests/mesh/test_MeshIO.py
+++ b/tests/mesh/test_MeshIO.py
@@ -1,5 +1,6 @@
 import numpy as np
-import unittest, os
+import unittest
+import os
 import SimPEG as simpeg
 from SimPEG.Mesh import TensorMesh, TreeMesh
 
@@ -8,7 +9,7 @@ class TestTensorMeshIO(unittest.TestCase):
 
     def setUp(self):
         h = np.ones(16)
-        mesh = TensorMesh([h,2*h,3*h])
+        mesh = TensorMesh([h, 2*h, 3*h])
         self.mesh = mesh
 
     def test_UBCfiles(self):
@@ -17,9 +18,9 @@ class TestTensorMeshIO(unittest.TestCase):
         # Make a vector
         vec = np.arange(mesh.nC)
         # Write and read
-        mesh.writeUBC('temp.msh', {'arange.txt':vec})
+        mesh.writeUBC('temp.msh', {'arange.txt': vec})
         meshUBC = TensorMesh.readUBC('temp.msh')
-        vecUBC  = meshUBC.readModelUBC('arange.txt')
+        vecUBC = meshUBC.readModelUBC('arange.txt')
 
         # The mesh
         assert mesh.__str__() == meshUBC.__str__()
@@ -27,12 +28,11 @@ class TestTensorMeshIO(unittest.TestCase):
         assert np.sum(vec - vecUBC) == 0
         assert np.all(np.array(mesh.h) - np.array(meshUBC.h) == 0)
 
-
-        vecUBC  = mesh.readModelUBC('arange.txt')
+        vecUBC = mesh.readModelUBC('arange.txt')
         assert np.sum(vec - vecUBC) == 0
 
         mesh.writeModelUBC('arange2.txt', vec + 1)
-        vec2UBC  = mesh.readModelUBC('arange2.txt')
+        vec2UBC = mesh.readModelUBC('arange2.txt')
         assert np.sum(vec + 1 - vec2UBC) == 0
 
         print 'IO of UBC tensor mesh files is working'
@@ -44,7 +44,7 @@ class TestTensorMeshIO(unittest.TestCase):
         mesh = self.mesh
         vec = np.arange(mesh.nC)
 
-        mesh.writeVTK('temp.vtr', {'arange.txt':vec})
+        mesh.writeVTK('temp.vtr', {'arange.txt': vec})
         meshVTR, models = TensorMesh.readVTK('temp.vtr')
 
         assert mesh.__str__() == meshVTR.__str__()
@@ -62,10 +62,10 @@ class TestOcTreeMeshIO(unittest.TestCase):
 
     def setUp(self):
         h = np.ones(16)
-        mesh = TreeMesh([h,2*h,3*h])
+        mesh = TreeMesh([h, 2*h, 3*h])
         mesh.refine(3)
-        mesh._refineCell([0,0,0,3])
-        mesh._refineCell([0,2,0,3])
+        mesh._refineCell([0, 0, 0, 3])
+        mesh._refineCell([0, 2, 0, 3])
         self.mesh = mesh
 
     def test_UBCfiles(self):
@@ -74,9 +74,9 @@ class TestOcTreeMeshIO(unittest.TestCase):
         # Make a vector
         vec = np.arange(mesh.nC)
         # Write and read
-        mesh.writeUBC('temp.msh', {'arange.txt':vec})
+        mesh.writeUBC('temp.msh', {'arange.txt': vec})
         meshUBC = TreeMesh.readUBC('temp.msh')
-        vecUBC  = meshUBC.readModelUBC('arange.txt')
+        vecUBC = meshUBC.readModelUBC('arange.txt')
 
         # The mesh
         assert mesh.__str__() == meshUBC.__str__()
@@ -90,11 +90,10 @@ class TestOcTreeMeshIO(unittest.TestCase):
     def test_VTUfiles(self):
         mesh = self.mesh
         vec = np.arange(mesh.nC)
-        mesh.writeVTK('temp.vtu',{'arange':vec})
+        mesh.writeVTK('temp.vtu', {'arange': vec})
         print 'Writing of VTU files is working'
         os.remove('temp.vtu')
 
 
-
 if __name__ == '__main__':
     unittest.main()
diff --git a/tests/mesh/test_TreeMesh.py b/tests/mesh/test_TreeMesh.py
index afad27d1..0e765587 100644
--- a/tests/mesh/test_TreeMesh.py
+++ b/tests/mesh/test_TreeMesh.py
@@ -6,6 +6,7 @@ import unittest
 
 TOL = 1e-8
 
+
 class TestSimpleQuadTree(unittest.TestCase):
 
     def test_counts(self):
diff --git a/tests/pf/test_magnetics_IO.py b/tests/pf/test_magnetics_IO.py
index d51fdac7..d291b8d4 100644
--- a/tests/pf/test_magnetics_IO.py
+++ b/tests/pf/test_magnetics_IO.py
@@ -12,7 +12,10 @@ class MagSensProblemTests(unittest.TestCase):
     def test_magnetics_inversion(self):
 
         driver = PF.MagneticsDriver.MagneticsDriver_Inv(
-            os.path.sep.join(['assets', 'magnetics', 'PYMAG3D_inv.inp'])
+            os.path.sep.join([
+                os.path.split(__file__)[0],
+                'assets', 'magnetics', 'PYMAG3D_inv.inp'
+            ])
         )
 
         print driver.mesh