use cmath instead of math and remove itertools import

Author: Aniketsy

Lib/test/test_cmath.py

@@ -2,7 +2,6 @@
 from test.support.testcase import ComplexesAreIdenticalMixin
 from test.test_math import parse_testfile, test_file
 import test.test_math as test_math
-import itertools
 import unittest
 import cmath, math
 from cmath import phase, polar, rect, pi
@@ -591,17 +590,17 @@ def test_complex_special(self):
         self.assertIsNotClose(-INF, INF)
         self.assertIsNotClose(0, INF)
         self.assertIsNotClose(0, INF*1j)
-        special = [INF, -INF, NAN]
+        special = [INF, -INF, NAN, 0.0, -0.0, 1.0]
         special_complex = [complex(x, y) for x in special for y in special]
 
         nan_complex = [c for c in special_complex
-                      if math.isnan(c.real) or math.isnan(c.imag)]
+                      if cmath.isnan(c.real) or cmath.isnan(c.imag)]
         for z in nan_complex:
             for w in special_complex:
                 self.assertIsNotClose(z, w)
 
         inf_complex = [c for c in special_complex
-                      if not math.isnan(c.real) and not math.isnan(c.imag)]
+                      if not cmath.isnan(c.real) and not cmath.isnan(c.imag)]
         for z in inf_complex:
             for w in inf_complex:
                 if z != w: