Piecewise should not expose raw memory. Closes #798.

1 files changed, 12 insertions, 7 deletions

diff --git a/numpy/lib/function_base.py b/numpy/lib/function_base.py
index e8df0b439..2204f1863 100644
--- a/numpy/lib/function_base.py
+++ b/numpy/lib/function_base.py
@@ -563,8 +563,11 @@ def piecewise(x, condlist, funclist, *args, **kw):
     """
     x = asanyarray(x)
     n2 = len(funclist)
-    if not isinstance(condlist, type([])):
+    if isscalar(condlist) or \
+           not (isinstance(condlist[0], list) or
+                isinstance(condlist[0], ndarray)):
         condlist = [condlist]
+    condlist = [asarray(c, dtype=bool) for c in condlist]
     n = len(condlist)
     if n == n2-1:  # compute the "otherwise" condition.
         totlist = condlist[0]
@@ -573,10 +576,11 @@ def piecewise(x, condlist, funclist, *args, **kw):
         condlist.append(~totlist)
         n += 1
     if (n != n2):
-        raise ValueError, "function list and condition list must be the same"
+        raise ValueError, "function list and condition list " \
+                          "must be the same"
     zerod = False
-    # This is a hack to work around problems with NumPy's 
-    #  handling of 0-d arrays and boolean indexing with 
+    # This is a hack to work around problems with NumPy's
+    #  handling of 0-d arrays and boolean indexing with
     #  numpy.bool_ scalars
     if x.ndim == 0:
         x = x[None]
@@ -589,7 +593,8 @@ def piecewise(x, condlist, funclist, *args, **kw):
                 condition = condlist[k]
             newcondlist.append(condition)
         condlist = newcondlist
-    y = empty(x.shape, x.dtype)
+
+    y = zeros(x.shape, x.dtype)
     for k in range(n):
         item = funclist[k]
         if not callable(item):
@@ -1090,7 +1095,7 @@ class vectorize(object):
             self.__doc__ = pyfunc.__doc__
         else:
             self.__doc__ = doc
-        if isinstance(otypes, types.StringType):
+        if isinstance(otypes, str):
             self.otypes = otypes
             for char in self.otypes:
                 if char not in typecodes['All']:
@@ -1121,7 +1126,7 @@ class vectorize(object):
             for arg in args:
                 newargs.append(asarray(arg).flat[0])
             theout = self.thefunc(*newargs)
-            if isinstance(theout, types.TupleType):
+            if isinstance(theout, tuple):
                 self.nout = len(theout)
             else:
                 self.nout = 1