diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..cc22ff1
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,5 @@
+build/
+dist/
+genutil.egg-info/
+tests/__pycache__/
+tests/.last_failure
diff --git a/Lib/__init__.py b/Lib/__init__.py
index 8b4315a..26dd70b 100644
--- a/Lib/__init__.py
+++ b/Lib/__init__.py
@@ -21,6 +21,7 @@
 import os  # noqa
 import sys  # noqa
 import cdat_info
+from .stats_checker import StatisticsError  # noqa
 
 # udunits bits
 from .udunits import udunits, addBaseUnit, addDimensionlessUnit, addScaledUnit  # noqa
diff --git a/Lib/averager.py b/Lib/averager.py
index 196726f..0c62e1d 100644
--- a/Lib/averager.py
+++ b/Lib/averager.py
@@ -11,14 +11,7 @@
 
 
 class AveragerError (Exception):
-    def __init__(self, args=None):
-        """Create an exception"""
-        self.args = args
-
-    def __str__(self):
-        """Calculate the string representation"""
-        return str(self.args)
-    __repr__ = __str__
+    pass
 
 
 def _check_axisoptions(x, axisoptions):
@@ -442,7 +435,7 @@ def __check_weightoptions(x, axisoptions, weightoptions):
     if __DEBUG__:
         print('axislist = ', axislist)
     #
-    if not isinstance(weightoptions, list):
+    if not isinstance(weightoptions, (list, tuple)):
         #
         # We have either 1 axis only or multiple axes and one MV2 of weights
         #
@@ -490,6 +483,11 @@ def __check_weightoptions(x, axisoptions, weightoptions):
         #
         # We have multiple axes to deal with each with a weight....
         #
+
+        # Ensure we have a mutable list, handles tuple (https://github.com/CDAT/genutil/issues/32
+        if not isinstance(weightoptions, list):
+            weightoptions = list(weightoptions)
+
         for i in range(len(axislist)):
             weightoptions[i] = __check_each_weight_option(
                 x, axislist[i], axisindex[i], weightoptions[i])
diff --git a/Lib/stats_checker.py b/Lib/stats_checker.py
index b663919..c2a978c 100644
--- a/Lib/stats_checker.py
+++ b/Lib/stats_checker.py
@@ -5,15 +5,7 @@
 
 
 class StatisticsError(Exception):
-    def __init__(self, args=None):
-        """Create an exception"""
-        self.args = args
-
-    def __str__(self):
-        """Calculate the string representation"""
-        return str(self.args)
-
-    __repr__ = __str__
+    pass
 
 
 def __makeweights(x, w, axes):
diff --git a/tests/test_genutil_averager.py b/tests/test_genutil_averager.py
index 3749d57..0504972 100644
--- a/tests/test_genutil_averager.py
+++ b/tests/test_genutil_averager.py
@@ -6,6 +6,13 @@
 import unittest
 
 class GENUTIL(unittest.TestCase):
+    def testError(self):
+        error = AveragerError("Custom error message")
+
+        print(str(error))
+
+        self.assertTrue(str(error) == "Custom error message")
+
     def testAverager(self):
         f=cdms2.open(os.path.join(cdat_info.get_sampledata_path(),'tas_ukmo_con.nc'))
         x = f('tas')
diff --git a/tests/test_genutil_stats_missing.py b/tests/test_genutil_stats_missing.py
index 0d1e825..cc3fc0b 100644
--- a/tests/test_genutil_stats_missing.py
+++ b/tests/test_genutil_stats_missing.py
@@ -4,6 +4,11 @@
 import numpy
 
 class GENUTIL(unittest.TestCase):
+    def testError(self):
+        error = genutil.StatisticsError("Custom error message")
+
+        self.assertTrue(str(error) == "Custom error message")
+
     def testStatsMissing(self):
         a=MV2.array([1,2,3,4,5],mask=[0,0,1,0,0])
         self.assertTrue(numpy.allclose(genutil.statistics.std(a),1.58113883008))