phthon 계산기 예제

def calculate(expression):
    operators = []
    operands = []
    i = 0

    while i < len(expression):
        token = expression[i]

        if token.isdigit():
            num = ""
            while i < len(expression) and expression[i].isdigit():
                num += expression[i]
                i += 1
            operands.append(int(num))
        elif token == '+':
            operators.append(token)
            i += 1
        elif token == '-':
            operators.append(token)
            i += 1
        elif token == '*':
            operators.append(token)
            i += 1
        elif token == '/':
            operators.append(token)
            i += 1
        elif token == '(':
            operators.append(token)
            i += 1
        elif token == ')':
            while operators and operators[-1] != '(':
                process_operator(operators, operands)
            operators.pop()  # Remove the '('
            i += 1

    while operators:
        process_operator(operators, operands)

    return operands[0]

def process_operator(operators, operands):
    operator = operators.pop()
    operand2 = operands.pop()
    operand1 = operands.pop()
    if operator == '+':
        operands.append(operand1 + operand2)
    elif operator == '-':
        operands.append(operand1 - operand2)
    elif operator == '*':
        operands.append(operand1 * operand2)
    elif operator == '/':
        operands.append(operand1 / operand2)

user_input = input("수식을 입력하세요: ")
expression = user_input.replace(" ", "")
result = calculate(expression)
print("결과:", result)