250509calc correct

def check_operand(operand):
    try:
        return float(operand)
    except ValueError:
        print("wrong input value")
        return None
def check_operator(operator):
    if operator in ["+",'-',"*",'/']:
        return True
    else:
        print("worng operator !")
        return None
def check_odd(length):
    if length % 2 and length >=3:
        return True
    else:
        return False
expression = input("Please input expression with space for calculation :")
expression = expression.split()
# check a valid expression bdfore jump into while loop
if check_odd(len(expression)):
    #valid length of expression
    while(check_odd(len(expression))):
        # argement = parameter
        # length = len(expression)
        x = expression[0]
        op = expression[1]
        y = expression[2]
        # check first operand or exit the while loop witho
        if check_operand(x):
            x = check_operand(x)
        else:
            break
        # check second operand or exit the while loop
        if check_operand(y):
            y = check_operand(y)
        else:
            break
        #final check of opertor then perform calculation
        if check_operand(op):
            if op == '+':
                result = x + y
            if op == '-':
                result = x - y
            if op == '*':
                result = x * y
            if op == '/':
                if y == 0:
                    print("value overflow !")
                    break
                else:
                    result  = x / y
        else:
            print("invalid operator")
            break
        del expresssion[:2]
        expression[0] = result
    else: # if expression is short then print the final result
        print(f"The expression result is : {result}")
else:
    print("invalid expression, can't calculate !")