Merge pull request #7328 from emilienkofman/master

DEP: Deprecated using a float index in linspace

2 files changed, 32 insertions, 1 deletions

diff --git a/numpy/core/function_base.py b/numpy/core/function_base.py
index 21ca1af01..750fbe838 100644
--- a/numpy/core/function_base.py
+++ b/numpy/core/function_base.py
@@ -1,10 +1,24 @@
 from __future__ import division, absolute_import, print_function
 
+import warnings
+import operator
+
 __all__ = ['logspace', 'linspace']
 
 from . import numeric as _nx
 from .numeric import result_type, NaN, shares_memory, MAY_SHARE_BOUNDS, TooHardError
 
+def _index_deprecate(i, stacklevel=2):
+    try:
+        i = operator.index(i)
+    except TypeError:
+        msg = ("object of type {} cannot be safely interpreted as "
+               "an integer.".format(type(i)))
+        i = int(i)
+        stacklevel += 1
+        warnings.warn(msg, DeprecationWarning, stacklevel=stacklevel)
+    return i
+
 
 def linspace(start, stop, num=50, endpoint=True, retstep=False, dtype=None):
     """
@@ -81,7 +95,8 @@ def linspace(start, stop, num=50, endpoint=True, retstep=False, dtype=None):
     >>> plt.show()
 
     """
-    num = int(num)
+    # 2016-02-25, 1.12
+    num = _index_deprecate(num)
     if num < 0:
         raise ValueError("Number of samples, %s, must be non-negative." % num)
     div = (num - 1) if endpoint else num
diff --git a/numpy/core/tests/test_deprecations.py b/numpy/core/tests/test_deprecations.py
index ee65bc432..3a4c05136 100644
--- a/numpy/core/tests/test_deprecations.py
+++ b/numpy/core/tests/test_deprecations.py
@@ -578,6 +578,22 @@ class TestArrayDataAttributeAssignmentDeprecation(_DeprecationTestCase):
         self.assert_deprecated(a.__setattr__, args=('data', b.data))
 
 
+class TestLinspaceInvalidNumParameter(_DeprecationTestCase):
+    """Argument to the num parameter in linspace that cannot be 
+    safely interpreted as an integer is deprecated in 1.12.0.
+
+    Argument to the num parameter in linspace that cannot be 
+    safely interpreted as an integer should not be allowed. 
+    In the interest of not breaking code that passes
+    an argument that could still be interpreted as an integer, a
+    DeprecationWarning will be issued for the time being to give 
+    developers time to refactor relevant code.
+    """
+    def test_float_arg(self):
+        # 2016-02-25, PR#7328
+        self.assert_deprecated(np.linspace, args=(0, 10, 2.5))
+
+
 class TestTestDeprecated(object):
     def test_assert_deprecated(self):
         test_case_instance = _DeprecationTestCase()