我正在尝试构建一个抑制 stdout 和 stderr 的类。 当用作 with statement
时,我把它放下了但我想扩展功能以用作装饰器,我可以用它来抑制函数的输出。是否可以将所有内容完全包含在类中,或者包装器是否需要成为类之外的函数?
我正在尝试遵循这些资源,但很难适应我的情况:
https://stackabuse.com/pythons-classmethod-and-staticmethod-explained/
How to implement Python decorator with arguments as a class?
import os,sys, functools
class Suppress(object):
def __init__(self, show_stdout=False, show_stderr=False):
self.show_stdout = show_stdout
self.show_stderr = show_stderr
self.original_stdout = None
self.original_stderr = None
def __enter__(self):
devnull = open(os.devnull, "w")
# Suppress streams
if not self.show_stdout:
self.original_stdout = sys.stdout
sys.stdout = devnull
if not self.show_stderr:
self.original_stderr = sys.stderr
sys.stderr = devnull
def __exit__(self, *args, **kwargs):
# Restore streams
if not self.show_stdout:
sys.stdout = self.original_stdout
if not self.show_stderr:
sys.stderr = self.original_stderr
def __call__(self, *args, **kwargs):
def decorator(func):
@functools.wraps(func)
def wrapper(*args, **kwargs):
with self(*args, **kwargs):
return func(*args, **kwargs)
return wrapper
return decorator
with Suppress(show_stdout=False, show_stderr=False):
print("stdout", file=sys.stdout)
print("stderr", file=sys.stderr)
我试图也有这个功能作为装饰器:
@Suppress(show_stdout=True)
def f(x, y):
print(x, file=sys.stdout)
print(y, file=sys.stderr)
return x*y
a = f(1,2)
# 1
# a = 2
我有一个类似的装饰器(虽然非常丑陋)为
matplotlib
工作样式包装器。但是,这必须使用外部函数并且不在类内。# # Decorators
# def stylize(style="seaborn-white"):
# def decorator(func):
# @functools.wraps(func)
# def wrapper(*args, **kwargs):
# with plt.style.context(style):
# return func(*args, **kwargs)
# return wrapper
# return decorator
# # Wrappers
# def subplots_wrapper(style="seaborn-white", *args, **kwargs):
# @stylize(style)
# def inner_wrapper(*args, **kwargs):
# return plt.subplots(*args, **kwargs)
# return inner_wrapper(*args, **kwargs)
最佳答案
如果您只使用 with self
,它会起作用没有参数:
def __call__(self, function):
@functools.wraps(function)
def decorated(*args, **kwargs):
with self:
return function(*args, **kwargs)
return decorated
关于python - 如何在 "decorator"对象中实现 "class"功能?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/61685971/