用python写出一个以罚息的按月分段计算复利的代码

当然，下面是一个简单的Python代码示例，用于计算每月按照固定利率的复利利息，假设每个月都有固定的一次计息机会：

def calculate_interest(principal, rate, months, penalty_rate):
    # 初始本金
    principal_remaining = principal
    # 总利息
    total_interest = 0

    for month in range(1, months + 1):
        # 计算普通月的利息
        interest = (principal_remaining * rate) / 12
        # 罚息情况处理
        if month % 6 == 1:  # 每六个月有一次额外罚息
            interest += (principal_remaining * penalty_rate) / 12
        # 更新本金加上当月利息
        principal_remaining += interest
        total_interest += interest

    return total_interest, principal_remaining

# 示例使用
principal = 10000  # 本金
annual_rate = 0.05  # 年利率
months = 36  # 贷款总月数
penalty_rate = 0.01  # 罚息率每半年一次

interest_calculated, final_amount = calculate_interest(principal, annual_rate, months, penalty_rate)
print(f"总利息: {interest_calculated:.2f}, 最终余额: {final_amount:.2f}")