你这个代码在spyder上报错了 提示IndexError: list index out of range

抱歉，可能是由于表达式中有空格或其他非法字符导致解析出错。我修改了代码，增加了对表达式中非法字符的处理，同时还添加了一些注释来帮助理解。

def calculate(expression):
    # 将中缀表达式转换为逆波兰表达式
    output = []
    stack = []
    for token in expression.split():
        if token.isdigit():
            output.append(token)
        elif token in {'+', '-', '*', '/'}:
            while stack and stack[-1] != '(' and (token in {'*', '/'}
                    or stack[-1] in {'+', '-'}):
                output.append(stack.pop())
            stack.append(token)
        elif token == '(':
            stack.append(token)
        elif token == ')':
            while stack and stack[-1] != '(':
                output.append(stack.pop())
            if stack and stack[-1] == '(':
                stack.pop()
        else:
            # 非法字符，直接跳过
            continue
    while stack:
        output.append(stack.pop())
    # 计算逆波兰表达式的值
    stack = []
    for token in output:
        if token.isdigit():
            stack.append(int(token))
        elif token == '+':
            b = stack.pop()
            a = stack.pop()
            stack.append(a + b)
        elif token == '-':
            b = stack.pop()
            a = stack.pop()
            stack.append(a - b)
        elif token == '*':
            b = stack.pop()
            a = stack.pop()
            stack.append(a * b)
        elif token == '/':
            b = stack.pop()
            a = stack.pop()
            stack.append(int(a / b))
    if stack:
        return stack[0]
    else:
        # 栈为空，表达式有误，返回None
        return None

expression = '2*((60-30+(-40/5)*(9-2*5/3+7/3*99/4*2998+10*568/14))'
result = calculate(expression)
print(result)

请注意，在处理非法字符时，我采用了直接跳过的方式，如果你需要对表达式中的非法字符进行处理，请根据实际需求进行修改。