BUG: Issue #7852. raising TypeError from set_printoptions for incorre…

…ct first arg type
numpy · tom-bird · Jul 21, 2016 · Jul 28, 2016 · Jul 25, 2016 · 816978d4f17eaf015a8b5f5d6fcabd534eff6019
commit 816978d4f17eaf015a8b5f5d6fcabd534eff6019
diff --git a/numpy/core/arrayprint.py b/numpy/core/arrayprint.py
@@ -59,6 +59,9 @@ def set_printoptions(precision=None, threshold=None, edgeitems=None,
     ----------
     precision : int, optional
         Number of digits of precision for floating point output (default 8).
+        We type check this argument, as it is the first argument and we wish to
+        catch the common mistake of passing an unpacked dict (which will later
+        cause print() to fail with an opaque error).
     threshold : int, optional
         Total number of array elements which trigger summarization
         rather than full repr (default 1000).
@@ -161,6 +164,8 @@ def set_printoptions(precision=None, threshold=None, edgeitems=None,
     if edgeitems is not None:
         _summaryEdgeItems = edgeitems
     if precision is not None:
+        if not isinstance(precision
8000
, int):
+            raise TypeError("set_printoptions requires the argument 'precision' to be of type int")
         _float_output_precision = precision
     if suppress is not None:
         _float_output_suppress_small = not not suppress

diff --git a/numpy/core/tests/test_arrayprint.py b/numpy/core/tests/test_arrayprint.py
@@ -7,7 +7,7 @@
 import numpy as np
 from numpy.compat import sixu
 from numpy.testing import (
-     TestCase, run_module_suite, assert_, assert_equal
+     TestCase, run_module_suite, assert_, assert_equal, assert_raises
 )
 
 class TestArrayRepr(object):
@@ -157,6 +157,10 @@ def test_formatter_reset(self):
         np.set_printoptions(formatter={'float_kind':None})
         assert_equal(repr(x), "array([ 0.,  1.,  2.])")
 
+    def test_type_check(self):
+        d = {}
+        assert_raises(TypeError, np.set_printoptions, d)
+
 def test_unicode_object_array():
     import sys
     if sys.version_info[0] >= 3: