import functools
def log(t='call'):
    def deco(func):
        @functools.wraps(func)
        def wrapper(*args, **kw):
            print('begin %s %s():' % (t,func.__name__))
            func(*args, **kw)
            print('end call')
        return wrapper
    return deco

@log('execute')
def f():
    print('hello')

f()