def debug(func):  
    def wrapper(*args, **kwargs):  
        print 'debug start'  
        ret = func(*args, **kwargs)  
        print 'debug end'  
        return ret  
    return wrapper  
  
@debug  
def foo(arg1, arg2):  
    print 'foo', arg1, arg2 

def debug(level=1):  
    def wrapper(func):  
        def inner_wrapper(*args, **kwargs):  
            print 'debug start(level=%s)' % level  
            ret = func(*args, **kwargs)  
            print 'debug end(level=%s)' % level  
            return ret  
        return inner_wrapper  
    return wrapper  
  
@debug(3)  
def foo1(arg1, arg2):  
    print 'foo1', arg1, arg2  
  
@debug()  
def foo1(arg1, arg2):  
    print 'foo2', arg1, arg2