我们可以编写一个名为“show_status”的函数，它将取决于三个参数：当前消费，总消费和可用余额。函数将计算可用余额以及当前消费与总消费之间的百分比，并将结果输出为字符串。

以下是代码示例：

def show_status(current_expense, total_expense, balance):
    used_percentage = current_expense / total_expense * 100
    available_balance = balance - current_expense
    
    if used_percentage > 100:
        return "Total expenses exceeded. Please check your budget."
    elif used_percentage >= 80:
        return f"Warning: Your current expenses account for {used_percentage}% of your total budget. Available balance: {available_balance}."
    else:
        return f"Your current expenses account for {used_percentage}% of your total budget. Available balance: {available_balance}."

# 示例用法
current_expense = 100
total_expense = 500
balance = 5000
print(show_status(current_expense, total_expense, balance))
# 输出结果: Your current expenses account for 20.0% of your total budget. Available balance: 4900.

current_expense = 600
total_expense = 500
balance = 5000
print(show_status(current_expense, total_expense, balance))
# 输出结果: Total expenses exceeded. Please check your budget.

current_expense = 4000
total_expense = 5000
balance = 10000
print(show_status(current_expense, total_expense, balance))
# 输出结果: Warning: Your current expenses account for 80.0% of your total budget. Available balance: 6000.