def test_balanced(self):
     self.assertTrue(prop_parens('(((())))') == 0)
 def test_parens2(self):
     self.assertTrue(prop_parens(')') == -1)
 def test_no_parens(self):
     self.assertTrue(prop_parens('parentheses') == 0)
 def test_parens1(self):
     self.assertTrue(prop_parens('(') == 1)
 def test_empty_string(self):
     self.assertTrue(prop_parens('') == 0)
 def test_wrong_order(self):
     self.assertTrue(prop_parens('))()((') == -1)
 def test_broken(self):
     self.assertTrue(prop_parens('())))') == -1)
 def test_open(self):
     self.assertTrue(prop_parens('((((((()') == 1)