diff --git a/minpower/experiments/ed_sweep.py b/minpower/experiments/ed_sweep.py
index 51f3fc50..2d551604 100644
--- a/minpower/experiments/ed_sweep.py
+++ b/minpower/experiments/ed_sweep.py
@@ -42,7 +42,7 @@ def main(args):
 
         results.ix[load_val, 'committed'] = statuses.sum()
         results.ix[load_val, 'last_committed'] = \
-            statuses[statuses == 1].index.diff(committed_gen_names)
+            statuses[statuses == 1].index.difference(committed_gen_names)
         committed_gen_names = statuses[statuses == 1].index
 
     if (load_values[-1] == 0.99 * gen_data.pmax.sum()) and \
diff --git a/minpower/generators.py b/minpower/generators.py
index c66c726c..7d9825e9 100644
--- a/minpower/generators.py
+++ b/minpower/generators.py
@@ -1,7 +1,7 @@
 import pandas as pd
 import logging
 from config import user_config
-from commonscripts import update_attributes, bool_to_int, set_trace
+from commonscripts import update_attributes, bool_to_int
 
 from optimization import value, OptimizationObject
 from schedule import is_init
diff --git a/minpower/get_data.py b/minpower/get_data.py
index e74aa607..17c2f3ec 100644
--- a/minpower/get_data.py
+++ b/minpower/get_data.py
@@ -286,7 +286,7 @@ def build_class_list(data, model, times=None, timeseries=None):
         valid_fields = pd.Index(fields[model.__name__] + ['schedulename'])
         if is_generator:
             valid_fields = valid_fields.union(pd.Index(gen_extra_fields))
-        invalid_fields = row.index.diff(valid_fields)
+        invalid_fields = row.index.difference(valid_fields)
         if len(invalid_fields) > 0:
             raise ValueError('invalid fields in model:: {}'.format(
                 invalid_fields.tolist()))
diff --git a/minpower/optimization.py b/minpower/optimization.py
index 0ef095ec..e381972f 100644
--- a/minpower/optimization.py
+++ b/minpower/optimization.py
@@ -149,13 +149,11 @@ def add_parameter(self, name, index=None, values=None, mutable=True, default=Non
     def add_constraint(self, name, time, expression):
         '''Create a new constraint and add it to the object's constraints and the model's constraints.'''
         cname = self._t_id(name, time)
-        self._parent_problem().add_component_to_problem(
-            pyomo.Constraint(name=cname, rule=expression))
+        self._parent_problem().add_component_to_problem(pyomo.Constraint(name=cname, expr=expression))
 
     def add_constraint_set(self, name, index, expression):
         cname = self._id(name)
-        self._parent_problem().add_component_to_problem(
-            pyomo.Constraint(index, name=cname, rule=expression))
+        self._parent_problem().add_component_to_problem(pyomo.Constraint(index, name=cname, rule=expression))
 
     def get_dual(self, cname, time=None):
         '''get the dual of a constraint of an LP problem'''
@@ -287,13 +285,11 @@ def add_component_to_problem(self, component):
 
     def add_objective(self, expression, sense=pyomo.minimize):
         '''add an objective to the problem'''
-        self._model.objective = pyomo.Objective(
-            name='objective', rule=expression, sense=sense)
+        self._model.objective = pyomo.Objective(name='objective', expr=expression, sense=sense)
 
     def add_set(self, name, items, ordered=False):
         '''add a :class:`pyomo.Set` to the problem'''
-        self._model.add_component(name,
-                                  pyomo.Set(initialize=items, name=name, ordered=ordered))
+        self._model.add_component(name, pyomo.Set(initialize=items, name=name, ordered=ordered))
 
     def add_variable(self, name, **kwargs):
         '''create a new variable and add it to the root problem'''
@@ -304,12 +300,10 @@ def map_args(kind='Continuous', low=None, high=None):
 
     def add_constraint(self, name, expression, time=None):
         cname = self._t_id(name, time) if time is not None else name
-        self._model.add_component(cname,
-                                  pyomo.Constraint(name=name, rule=expression))
+        self._model.add_component(cname, pyomo.Constraint(name=name, expr=expression))
 
     def add_suffix(self, name):
-        self._model.add_component(name,
-                                  pyomo.Suffix(direction=pyomo.Suffix.IMPORT))
+        self._model.add_component(name, pyomo.Suffix(direction=pyomo.Suffix.IMPORT))
 
     def get_component(self, name, scenario=None):
         '''Get an optimization component'''
diff --git a/minpower/solve.py b/minpower/solve.py
index 7fd3d20d..938660be 100644
--- a/minpower/solve.py
+++ b/minpower/solve.py
@@ -15,7 +15,7 @@
 import pdb
 
 from config import user_config, parse_command_line_config
-from commonscripts import joindir, StreamToLogger, set_trace
+from commonscripts import joindir, StreamToLogger
 import powersystems
 import get_data
 import stochastic
@@ -263,7 +263,7 @@ def _setup_logging(pid=None):
             and not user_config.debugger:
         kwds['filename'] = joindir(user_config.directory,
                                    '{}.log'.format(pid))
-    if (user_config.logging_level > 10) and (not 'filename' in kwds):
+    if (user_config.logging_level > 10) and ('filename' not in kwds):
         # don't log the time if debugging isn't turned on
         kwds['format'] = '%(levelname)s: %(message)s'
     logging.basicConfig(**kwds)
diff --git a/minpower/tests/memory_leak_check.py b/minpower/tests/memory_leak_check.py
index ec7c3857..01281b44 100644
--- a/minpower/tests/memory_leak_check.py
+++ b/minpower/tests/memory_leak_check.py
@@ -1,9 +1,6 @@
 '''Test for memory leaks'''
 from minpower import powersystems, solve
 from test_utils import solve_problem, make_loads_times
-from coopr import pyomo
-
-
 import objgraph
 import inspect