Python Errors and Exceptions

http://www.cnblogs.com/xuqiang/archive/2011/04/30/2033579.html

1. python中的try{}catch{}

2. raise exception

3. try...except ... else.. 

4. finally块 

1. python中的try{}catch{}

python中的异常处理的关键字和c#中的是不相同的，python中使用try，except关键在来处理异常，如下：

def dive(x, y):
    try:
        result = x / y;
    except ZeroDivisionError as z :
            print("division by zero.", z);
    else:
        print("the result is ", result);
    finally:
        print("executing finally caluse.");

 

2. raise excepption

python中如果在except中如果需要将异常重新抛出可以使用关键字raise，类似于c#中的throw关键字。

def raise_test():
    try:
        result = 1 / 0;
    except ZeroDivisionError :
        print ("can not process the exception, to throw ...");
        raise;
    finally:
        print("in finally block");
raise_test(); 

3. try...except ... else..

 

It is useful for code that must be executed if the try clause does not raise an exception

else块是说如果异常没有被抛出的情况下将被执行。

4. finally块 

 

A finally clauseis always executed before leaving thetrystatement

finally块是一定会被执行的，不论异常是否产生。