模拟分期还款（II）

在上一题的基础上，您决定扩展程序，记录每期的本金和利息偿还额，并将结果绘制成图，而不是只打印出来。

本例中，绘图代码已经提供。您只需完成 for 循环中的逻辑，以及每次迭代都会更新的变量初始化。

本练习是课程的一部分

Python 金融概念入门

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练习说明

逐期保存 interest_paid 和 principal_paid。
根据当期的本金偿还额和剩余本金，计算每期的 principal_remaining。
运行提供的代码，绘制每月利息与本金偿还额对比图。

交互式实操练习

通过完成这段示例代码来试试这个练习。

# Loop through each mortgage payment period
for i in range(0, mortgage_payment_periods):
    
    # Handle the case for the first iteration
    if i == 0:
        previous_principal_remaining = mortgage_loan
    else:
        previous_principal_remaining = principal_remaining[i-1]
        
    # Calculate the interest based on the previous principal
    interest_payment = round(previous_principal_remaining*mortgage_rate_periodic, 2)
    principal_payment = round(periodic_mortgage_payment - interest_payment, 2)
    
    # Catch the case where all principal is paid off in the final period
    if previous_principal_remaining - principal_payment < 0:
        principal_payment = previous_principal_remaining
        
    # Collect the historical values
    interest_paid[i] = ____
    principal_paid[i] = ____
    principal_remaining[i] = ____
    
# Plot the interest vs principal
plt.plot(interest_paid, color="red")
plt.plot(principal_paid, color="blue")
plt.legend(handles=[interest_plot, principal_plot], loc=2)
plt.show()

编辑并运行代码