Select should not modify output arguments. Add test for basic select functionality.

2 files changed, 17 insertions, 5 deletions

diff --git a/numpy/lib/function_base.py b/numpy/lib/function_base.py
index e038a4803..5d0d7c1a6 100644
--- a/numpy/lib/function_base.py
+++ b/numpy/lib/function_base.py
@@ -286,9 +286,7 @@ def histogramdd(sample, bins=10, range=None, normed=False, weights=None):
 
 
 def average(a, axis=None, weights=None, returned=False):
-    """average(a, axis=None weights=None, returned=False)
-
-    Average the array over the given axis.  If the axis is None,
+    """Average the array over the given axis.  If the axis is None,
     average over all dimensions of the array.  Equivalent to
     a.mean(axis) and to
 
@@ -452,7 +450,7 @@ def select(condlist, choicelist, default=0):
     n2 = len(choicelist)
     if n2 != n:
         raise ValueError, "list of cases must be same length as list of conditions"
-    choicelist.insert(0, default)
+    choicelist = [default] + choicelist
     S = 0
     pfac = 1
     for k in range(1, n+1):
diff --git a/numpy/lib/tests/test_function_base.py b/numpy/lib/tests/test_function_base.py
index f0930ae5b..b22ce1318 100644
--- a/numpy/lib/tests/test_function_base.py
+++ b/numpy/lib/tests/test_function_base.py
@@ -64,6 +64,20 @@ class test_average(NumpyTestCase):
         desired = array([3.,4.,5.])
         assert_array_equal(actual, desired)
 
+class test_select(NumpyTestCase):
+    def check_basic(self):
+        choices = [array([1,2,3]),
+                   array([4,5,6]),
+                   array([7,8,9])]
+        conditions = [array([0,0,0]),
+                      array([0,1,0]),
+                      array([0,0,1])]
+        assert_array_equal(select(conditions,choices,default=15),
+                           [15,5,9])
+
+        assert_equal(len(choices),3)
+        assert_equal(len(conditions),3)
+
 class test_logspace(NumpyTestCase):
     def check_basic(self):
         y = logspace(0,6)
@@ -431,4 +445,4 @@ def compare_results(res,desired):
         assert_array_equal(res[i],desired[i])
 
 if __name__ == "__main__":
-    NumpyTest('numpy.lib.function_base').run()
+    NumpyTest().run()