diff --git a/gtsam/discrete/discrete.i b/gtsam/discrete/discrete.i
index 55c8f9e227..b2e2524f8b 100644
--- a/gtsam/discrete/discrete.i
+++ b/gtsam/discrete/discrete.i
@@ -61,14 +61,14 @@ virtual class DecisionTreeFactor : gtsam::DiscreteFactor {
   DecisionTreeFactor(const std::vector<gtsam::DiscreteKey>& keys, string table);
 
   DecisionTreeFactor(const gtsam::DiscreteConditional& c);
-  
+
   void print(string s = "DecisionTreeFactor\n",
              const gtsam::KeyFormatter& keyFormatter =
                  gtsam::DefaultKeyFormatter) const;
   bool equals(const gtsam::DecisionTreeFactor& other, double tol = 1e-9) const;
 
   size_t cardinality(gtsam::Key j) const;
-  
+
   double operator()(const gtsam::DiscreteValues& values) const;
   gtsam::DecisionTreeFactor operator*(const gtsam::DecisionTreeFactor& f) const;
   size_t cardinality(gtsam::Key j) const;
diff --git a/python/gtsam/tests/test_DecisionTreeFactor.py b/python/gtsam/tests/test_DecisionTreeFactor.py
index 12308bb3ce..a78d9c94af 100644
--- a/python/gtsam/tests/test_DecisionTreeFactor.py
+++ b/python/gtsam/tests/test_DecisionTreeFactor.py
@@ -13,9 +13,10 @@
 
 import unittest
 
+from gtsam.utils.test_case import GtsamTestCase
+
 from gtsam import (DecisionTreeFactor, DiscreteDistribution, DiscreteValues,
                    Ordering)
-from gtsam.utils.test_case import GtsamTestCase
 
 
 class TestDecisionTreeFactor(GtsamTestCase):
diff --git a/python/gtsam/tests/test_DiscreteBayesTree.py b/python/gtsam/tests/test_DiscreteBayesTree.py
index 2a9b6ea092..e08491faba 100644
--- a/python/gtsam/tests/test_DiscreteBayesTree.py
+++ b/python/gtsam/tests/test_DiscreteBayesTree.py
@@ -19,8 +19,8 @@
 
 import gtsam
 from gtsam import (DiscreteBayesNet, DiscreteBayesTreeClique,
-                   DiscreteConditional, DiscreteFactorGraph,
-                   DiscreteValues, Ordering)
+                   DiscreteConditional, DiscreteFactorGraph, DiscreteValues,
+                   Ordering)
 
 
 class TestDiscreteBayesNet(GtsamTestCase):
diff --git a/python/gtsam/tests/test_DiscreteConditional.py b/python/gtsam/tests/test_DiscreteConditional.py
index 241a5f0be9..6c9eb9aec2 100644
--- a/python/gtsam/tests/test_DiscreteConditional.py
+++ b/python/gtsam/tests/test_DiscreteConditional.py
@@ -13,9 +13,10 @@
 
 import unittest
 
-from gtsam import DecisionTreeFactor, DiscreteConditional, DiscreteKeys
 from gtsam.utils.test_case import GtsamTestCase
 
+from gtsam import DecisionTreeFactor, DiscreteConditional, DiscreteKeys
+
 # Some DiscreteKeys for binary variables:
 A = 0, 2
 B = 1, 2
diff --git a/python/gtsam/tests/test_DiscreteFactorGraph.py b/python/gtsam/tests/test_DiscreteFactorGraph.py
index d725ceac87..3053087b4e 100644
--- a/python/gtsam/tests/test_DiscreteFactorGraph.py
+++ b/python/gtsam/tests/test_DiscreteFactorGraph.py
@@ -14,9 +14,12 @@
 import unittest
 
 import numpy as np
-from gtsam import DecisionTreeFactor, DiscreteConditional, DiscreteFactorGraph, DiscreteKeys, DiscreteValues, Ordering, Symbol
 from gtsam.utils.test_case import GtsamTestCase
 
+from gtsam import (DecisionTreeFactor, DiscreteConditional,
+                   DiscreteFactorGraph, DiscreteKeys, DiscreteValues, Ordering,
+                   Symbol)
+
 OrderingType = Ordering.OrderingType