Use operator.pow instead of math.pow for the decimal.Decimal objects

Author: zeroSteiner

lib/rule_engine/ast.py

@@ -776,7 +776,7 @@ def __op_arithmetic(self, op, thing):
 	_op_tdiv = functools.partialmethod(__op_arithmetic, operator.truediv)
 	_op_mod  = functools.partialmethod(__op_arithmetic, operator.mod)
 	_op_mul  = functools.partialmethod(__op_arithmetic, operator.mul)
-	_op_pow  = functools.partialmethod(__op_arithmetic, math.pow)
+	_op_pow  = functools.partialmethod(__op_arithmetic, operator.pow)
 
 class BitwiseExpression(LeftOperatorRightExpressionBase):
 	"""

tests/issues.py

@@ -72,3 +72,7 @@ def test_number_19(self):
 		)
 		rule = engine.Rule('facts.abc == "def"', context=context)
 		self.assertTrue(rule.matches({'facts': {'abc': 'def'}}))
+
+	def test_number_20(self):
+		rule = engine.Rule('a / b ** 2')
+		self.assertEqual(rule.evaluate({'a': 8, 'b': 4}), 0.5)