MathExpression.evaluate() get Error result

[xiuzhilu]

input_text = "4 + 9 / 8 * 9"
expr = ExpressionParser().parse(input_text)
print(expr.evaluate())
when I run this shell, I get 4.125. The result should be 14.125。The Calculation Order should :
9 / 8=1.125
1.125*9=10.125
4+10.125=14.12