异常处理

# 基本语法
try:
result = 10 / 0
except ZeroDivisionError:
print("不能除以零！")

# 捕获多个异常
try:
num = int(input("请输入数字: "))
except ValueError:
print("输入的不是有效数字")
except ZeroDivisionError:
print("不能除以零！")

# else 和 finally
try:
f = open("data.txt", "r")
except FileNotFoundError:
print("文件不存在")
else:
content = f.read()
finally:
  print("清理工作完成")

class InsufficientFundsError(Exception):
def __init__(self, balance, amount):
    self.balance = balance
    self.amount = amount
    super().__init__(f"余额不足: 当前 {balance}, 需要 {amount}")

def withdraw(balance, amount):
if amount > balance:
    raise InsufficientFundsError(balance, amount)
return balance - amount

try:
new_balance = withdraw(100, 200)
except InsufficientFundsError as e:
  print(e)