def test_div(num1,num2):

    return num1 / num2

if __name__ == "__main__":

    try:

        print(test_div(5,"a"))

    except ZeroDivisionError:

        print("除数不能为零")

    except TypeError as err:

        print("输入数字")

        print(err)

结果：

输入数字

unsupported operand type(s) for /: 'int' and 'str'

def test_file():

    try:

        f = open("test.txt","r")

        rest = f.read()

        print(rest)

    except:

        print("eror")

    finally:

        try:#加入新得try，防止文件没有被打开而需要关闭所产生的异常

            f.close()

            print("quan")

        except:

            pass

    #try:

if __name__ == "__main__":

    test_file()

class ApiException(Exception):

    """我的自定义异常"""

    err_code = ""

    err_msg = ""

    def __init__(self, err_code=None, err_msg=None):

        #111111如果存在则使用自己，要不就使用传进来的参数

        self.err_code = self.err_code if self.err_code else err_code

        self.err_msg = self.err_msg if self.err_msg else err_msg

    def __str__(self):

        return  "Error:{0} - {1}".format(self.err_code,self.err_msg)

class InvalidCtrlexec( ApiException):

    err_code = "4001"

    err_msg = "bbbbb"

class BagException(ApiException):

    err_code = "4002"

    err_msg = "quanzhiqiang"

def test_exec(num1,num2):

    """除法的实习"""

    #两个数必须为整数

    if not isinstance(num1,int) or not isinstance(num2,int):

        raise BagException()#BagException("88","9999")也是一样的输出，因为11111

    if num2 == 0:

        raise ApiException("40002","ccccc")

    return num1 / num2

if __name__ == "__main__":

    try:

        rest = test_exec(5,"2")

        """

        当为（5，0）结果：处处哦

        Error:40002 - ccccc

        当为（5，”quan”）结果为：

        quanqqqq

        Error:4002 - quanzhiqiang

        """

        print(rest)

    except BagException as B_err: #因为这个BagException是ApiException的子类，捕获小的再捕获大范围的

        print("quanqqqq")

        print(B_err)

    except ApiException as err:

        print("处处哦")

        print(err)

class MyException(Exception):

    pass

def v_for():

    for i in range(1,100):

        if i == 20:

            raise MyException

        print(i)

def call_v_for():

    print("aaaaaaaaaaaaaaaa")

    v_for()

    print("bbbbbbbbbbbbbbb")

def test_raise():

    print("ceshi")

    try:

        call_v_for()

    except MyException:

        print("88888888888888888")

    print("endend")

if __name__ == "__main__":

    test_raise()

结果：

ceshi

aaaaaaaaaaaaaaaa

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

88888888888888888

endend

因为异常是由原函数触发，如果没有捕获，就会一层一层往调用函数传递

这里在最外层捕获，所以call_v_for里面没有 print("bbbbbbbbbbbbbbb")