MAINT: Use normalize_axis_index in all python axis checking

As a result, some exceptions change from ValueError to IndexError

This also changes the exception types raised in places where
normalize_axis_index is not quite appropriate

1 files changed, 4 insertions, 7 deletions

diff --git a/numpy/core/numeric.py b/numpy/core/numeric.py
index 97d19f008..a5cb5bb31 100644
--- a/numpy/core/numeric.py
+++ b/numpy/core/numeric.py
@@ -17,7 +17,7 @@ from .multiarray import (
     inner, int_asbuffer, lexsort, matmul, may_share_memory,
     min_scalar_type, ndarray, nditer, nested_iters, promote_types,
     putmask, result_type, set_numeric_ops, shares_memory, vdot, where,
-    zeros)
+    zeros, normalize_axis_index)
 if sys.version_info[0] < 3:
     from .multiarray import newbuffer, getbuffer
 
@@ -1527,15 +1527,12 @@ def rollaxis(a, axis, start=0):
 
     """
     n = a.ndim
-    if axis < 0:
-        axis += n
+    axis = normalize_axis_index(axis, n)
     if start < 0:
         start += n
     msg = "'%s' arg requires %d <= %s < %d, but %d was passed in"
-    if not (0 <= axis < n):
-        raise ValueError(msg % ('axis', -n, 'axis', n, axis))
     if not (0 <= start < n + 1):
-        raise ValueError(msg % ('start', -n, 'start', n + 1, start))
+        raise IndexError(msg % ('start', -n, 'start', n + 1, start))
     if axis < start:
         # it's been removed
         start -= 1
@@ -1554,7 +1551,7 @@ def _validate_axis(axis, ndim, argname):
         axis = list(axis)
     axis = [a + ndim if a < 0 else a for a in axis]
     if not builtins.all(0 <= a < ndim for a in axis):
-        raise ValueError('invalid axis for this array in `%s` argument' %
+        raise IndexError('invalid axis for this array in `%s` argument' %
                          argname)
     if len(set(axis)) != len(axis):
         raise ValueError('repeated axis in `%s` argument' % argname)