如何理解Python的装饰器并实现一个简单的日志装饰器？

import functools
import logging

logging.basicConfig(level=logging.INFO, format='%(asctime)s - %(levelname)s - %(message)s')

def log_calls(func):
    @functools.wraps(func)  # 保留原函数的元信息
    def wrapper(*args, **kwargs):
        logging.info(f"Calling function: {func.__name__} with arguments: {args}, {kwargs}")
        result = func(*args, **kwargs)
        logging.info(f"Function {func.__name__} returned: {result}")
        return result
    return wrapper

@log_calls
def add(x, y):
    """This function adds two numbers."""
    return x + y

# 使用装饰器
result = add(5, 3)
print(result)

log_calls

func

wrapper

func

@functools.wraps(func)

func

__name__

__doc__

@log_calls

add = log_calls(add)

add(5, 3)

wrapper(5, 3)

import functools
import logging

def log_calls_level(level=logging.INFO):
    def log_decorator(func):
        @functools.wraps(func)
        def wrapper(*args, **kwargs):
            logging.log(level, f"Calling function: {func.__name__} with arguments: {args}, {kwargs}")
            result = func(*args, **kwargs)
            logging.log(level, f"Function {func.__name__} returned: {result}")
            return result
        return wrapper
    return log_decorator

@log_calls_level(level=logging.DEBUG) # 指定日志级别
def subtract(x, y):
    """This function subtracts two numbers."""
    return x - y

result = subtract(10, 4)
print(result)

log_calls_level

level

log_decorator

@log_calls_level(level=logging.DEBUG)

subtract = log_calls_level(level=logging.DEBUG)(subtract)

@classmethod

class MyClass:
    @log_calls
    @classmethod
    def my_class_method(cls):
        print("This is a class method")

MyClass.my_class_method()

@staticmethod

class MyClass:
    @log_calls
    @staticmethod
    def my_static_method():
        print("This is a static method")

MyClass.my_static_method()

@classmethod

@staticmethod