python异常处理

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异常名称描述
SystemExit解释器请求退出
FloatingPointError浮点计算错误
OverflowError数值运算超出最大限制
ZeroDivisionError除(或取模)零(所有数据型)
KeyboardInterrupt用户中断执行
ImportError导入模块/对象失败
IndexError序列中没有此索引(index)
RuntimeError一般的运行错误
AttributeError对象没有这个属性
IOError输入输出操作失败
OSError操作系统错误
KeyError映射中没有这个键
TypeError对类型无效的操作
ValueError传入无效的参数
Python异常处理格式
try:
    语句块1
except 异常类型1:
    语句块2
except 异常类型2:
    语句块3
.......

except 异常类型N:
    语句块 N+1
except:
    语句块N+2
else:
    语句块N+3
finally:
    语句块N+4

除数为零的异常

x = int(input())
y = int(input())
try:
    result = x / y
except ZeroDivisionError:
    print("division by zero")
else:
    print("result is", result)
finally:
    print("executing finally clause")

程序输入:
6
4
程序输出:
result is 1.5
executing finally clause

程序输入:
5
0
程序输出:
division by zero!
executing finally clause

获取整个对象的异常

short_list = [1,2,3]
while True:
    value = input('Position [q to quit]?')
    if value == 'q'
        break
    try:
        position = int(value)
        print(short_list[position])
    except IndexError as err:
        print('Bad index:',position)
    except Exception as other:
        print('Something else broke:',other)


程序输出:
Position [q to quit]? 1
2
Position [q to quit]? 3
Bad index:3
Position [q to quit]? one
Something else broke:
    invalid literal for int() with base 10:'one'
Position [q to quit]? Q

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