相关疑难解决方法(0)

我理解python中函数的装饰器(我可能错了)的方法是,它们应该添加副作用并修改函数的返回值.现在装饰器被添加到要装饰的函数的函数定义之上或通过赋值.这是一个小例子:

def print_args_decor(function):
    def wrapper(*args, **kwargs):
        print 'Arguments:', args, kwargs         # Added side-effect
        return function(*args, **kwargs)*5       # Modified return value
    return wrapper

@print_args_decor
def do_stuff(strg, n=10):
    """Repeats strg a few times."""
    return strg * n

new_decorated_func = print_args_decor(do_stuff)  # Decoration by assignment

print do_stuff('a', 2) # Output: aaaaaaaaaa

现在,如何将装饰器附加到其他地方定义的函数,理想情况下保留原始函数的名称和文档字符串(如同functools.wraps)？例如,我sqrt()从Python的数学模块导入函数,并想要装饰它,我该怎么做呢？

from functools import wraps
from math import sqrt

def print_args_decor(function):
    @wraps(function)
    def wrapper(*args, **kwargs):
        print 'Arguments:', args, kwargs         # Added side-effect
        return function(*args, …