帶引數的裝飾器-python
阿新 • • 發佈:2018-11-30
先來看看一般的情況
def use_logging(func):
def wrapper(*args, **kwargs):
if level == 'warn':
logging.warn('%s is running' % func.__name__)
return func(*args)
return wrapper
@use_logging
def foo(name = 'foo'):
print ('i am %s' % name)
foo()
@use_logging 相當於
foo = use_logging(foo), foo 指向了 return 的wrapper,
foo()相當於 wrapper(),直接運行了wrapper裡的內容以及func(*args)即def foo(name = ‘foo’)裡的內容。
理解了基本的,來看看帶引數的裝飾器
import logging
def use_logging(level):
def decorator(func):
def wrapper(*args, **kwargs):
if level == 'warn':
logging.warn('%s is running' % func.__name__)
return func(*args)
return wrapper
return decorator
@use_logging(level = 'warn' )
def foo(name = 'foo'):
print ('i am %s' % name)
foo()
@use_logging(level = ‘warn’)相當於 use_logging(level = ‘warn’)(foo)就相當於返回的decorator(foo),即foo = decorator(foo),其餘思路與上相同。