Python异常处理和异常类型 / 开普饭

python2.x捕获异常语法：

try:    ...some functions...except Exception, e:    print(e)

python3.x捕获异常语法：

try:    ...some functions...except Exception as e:    print(e)

注意这里 Exception, e 变成了 Exception as e

python常见的异常类型

1. NameError：尝试访问一个未申明的变量

>>> vNameError: name 'v' is not defined

2. ZeroDivisionError：除数为0

>>> v = 1/0ZeroDivisionError: int division or modulo by zero

3. SyntaxError：语法错误

int intSyntaxError: invalid syntax (<pyshell#14>, line 1)

4. IndexError：索引超出范围

List = [2]>>> List[3]Traceback (most recent call last):  File "<pyshell#18>", line 1, in <module>    List[3]IndexError: list index out of range

5. KeyError：字典关键字不存在

Dic = {'1':'yes', '2':'no'}>>> Dic['3']Traceback (most recent call last):  File "<pyshell#20>", line 1, in <module>    Dic['3']KeyError: '3'

6. IOError：输入输出错误

>>> f = open('abc')IOError: [Errno 2] No such file or directory: 'abc'

7. AttributeError：访问未知对象属性

>>> class Worker: def Work():  print("I am working")>>> w = Worker()>>> w.aTraceback (most recent call last):  File "<pyshell#51>", line 1, in <module>    w.aAttributeError: 'Worker' object has no attribute 'a'

8.ValueError：数值错误

>>> int('d')Traceback (most recent call last):  File "<pyshell#54>", line 1, in <module>    int('d')ValueError: invalid literal for int() with base 10: 'd'

9. TypeError：类型错误

>>> iStr = '22'>>> iVal = 22>>> obj = iStr + iVal;Traceback (most recent call last):  File "<pyshell#68>", line 1, in <module>    obj = iStr + iVal;TypeError: Can't convert 'int' object to str implicitly

10. AssertionError：断言错误

>>> assert 1 != 1Traceback (most recent call last):  File "<pyshell#70>", line 1, in <module>    assert 1 != 1AssertionError

11.MemoryError:内存耗尽异常

12. NotImplementedError：方法没实现引起的异常

class Base(object):    def __init__(self):        pass    def action(self):        #抛出异常，说明该接口方法未实现        raise NotImplementedError

13. LookupError：键、值不存在引发的异常

LookupError异常是IndexError、KeyError的基类，如果你不确定数据类型是字典还是列表时，可以用LookupError捕获此异常

14. StandardError 标准异常

除StopIteration, GeneratorExit, KeyboardInterrupt 和SystemExit外，其他异常都是StandarError的子类。

错误检测与异常处理区别在于：错误检测是在正常的程序流中，处理不可预见问题的代码，例如一个调用操作未能成功结束。

Python异常处理和异常类型