BUG: float arrays with no non-zero elements break legacy mode

ahaldane · ahaldane · commit abfddda6487d · 2017-11-17T16:20:27.000-05:00
Fixes #10026
diff --git a/numpy/core/arrayprint.py b/numpy/core/arrayprint.py
@@ -710,8 +710,8 @@ def fillFormat(self, data):
         with errstate(all='ignore'):
             hasinf = isinf(data)
             special = isnan(data) | hasinf
-            valid = not_equal(data, 0) & ~special
-            non_zero = data[valid]
+            non_special = data[~special]
+            non_zero = non_special[non_special != 0]
             abs_non_zero = absolute(non_zero)
             if len(non_zero) == 0:
                 max_val = 0.
@@ -727,7 +727,7 @@ def fillFormat(self, data):
                                            or max_val/min_val > 1000.):
                     self.exp_format = True
 
-        if len(non_zero) == 0:
+        if len(non_special) == 0:
             self.pad_left = 0
             self.pad_right = 0
             self.trim = '.'
@@ -740,7 +740,7 @@ def fillFormat(self, data):
                 trim, unique = 'k', False
             strs = (dragon4_scientific(x, precision=self.precision,
                                unique=unique, trim=trim, sign=self.sign == '+')
-                    for x in non_zero)
+                    for x in non_special)
             frac_strs, _, exp_strs = zip(*(s.partition('e') for s in strs))
             int_part, frac_part = zip(*(s.split('.') for s in frac_strs))
             self.exp_size = max(len(s) for s in exp_strs) - 1
@@ -751,7 +751,7 @@ def fillFormat(self, data):
             # for back-compatibility with np 1.13, use two spaces and full prec
             if self._legacy == '1.13':
                 # undo addition of sign pos below
-                will_add_sign = all(non_zero > 0) and self.sign == ' '
+                will_add_sign = all(non_special > 0) and self.sign == ' '
                 self.pad_left = 3 - will_add_sign
             else:
                 # this should be only 1 or two. Can be calculated from sign.
@@ -769,7 +769,7 @@ def fillFormat(self, data):
                                        fractional=True,
                                        unique=unique, trim=trim,
                                        sign=self.sign == '+')
-                    for x in non_zero)
+                    for x in non_special)
             int_part, frac_part = zip(*(s.split('.') for s in strs))
             self.pad_left = max(len(s) for s in int_part)
             self.pad_right = max(len(s) for s in frac_part)
@@ -784,7 +784,7 @@ def fillFormat(self, data):
                 self.trim = '.'
 
         # account for sign = ' ' by adding one to pad_left
-        if len(non_zero) > 0 and all(non_zero > 0) and self.sign == ' ':
+        if all(non_special >= 0) and self.sign == ' ':
             self.pad_left += 1
 
         if any(special):
diff --git a/numpy/core/tests/test_arrayprint.py b/numpy/core/tests/test_arrayprint.py
@@ -333,6 +333,7 @@ def test_sign_spacing(self):
         assert_equal(repr(a), 'array([0., 1., 2., 3.])')
         assert_equal(repr(np.array(1.)), 'array(1.)')
         assert_equal(repr(b), 'array([1.234e+09])')
+        assert_equal(repr(np.array([0.])), 'array([0.])')
 
         np.set_printoptions(sign=' ')
         assert_equal(repr(a), 'array([ 0.,  1.,  2.,  3.])')
@@ -349,6 +350,7 @@ def test_sign_spacing(self):
         assert_equal(repr(b),  'array([  1.23400000e+09])')
         assert_equal(repr(-b), 'array([ -1.23400000e+09])')
         assert_equal(repr(np.array(1.)), 'array(1.0)')
+        assert_equal(repr(np.array([0.])), 'array([ 0.])')
 
         assert_raises(TypeError, np.set_printoptions, wrongarg=True)
 
@@ -419,6 +421,7 @@ def test_floatmode(self):
         assert_equal(repr(w[::5]),
             "array([1.0000e+00, 1.0000e+05, 1.0000e+10, 1.0000e+15, 1.0000e+20])")
         assert_equal(repr(wp), "array([1.2340e+001, 1.0000e+002, 1.0000e+123])")
+        assert_equal(repr(np.zeros(3)), "array([0.0000, 0.0000, 0.0000])")
         # for larger precision, representation error becomes more apparent:
         np.set_printoptions(floatmode='fixed', precision=8)
         assert_equal(repr(z),
