Python装饰器

转自：https://www.cnblogs.com/astropeak/p/9029104.html

• 装饰器例
• 多重装饰

from functools import wraps

def trace(name):
  def wrapper(func):
    @wraps(func) #名称修正
    def wrapped(*args, **kwargs):
      print('Enter %s. Args: %s, kwargs: %s' % (name, args, kwargs))
      rv = func(*args, **kwargs)
      print('Exit %s. Return value: %s' % (name, rv))
      return rv

    return wrapped
  return wrapper

@trace('area')
def area(height, width):
  print('area called')
  return height * width

area(2, 3)

结果为

Enter area. Args: (2, 3), kwargs: {}
area called
Exit area. Return value: 6

@decSec
@decFir
def foo():pass

等价于：

def foo():pass
foo = decFir(foo)
foo = decSec(foo)