Python标准库中内置装饰器@staticmethod和@classmethod

# 定义一个装饰器函数
def my_decorator(func):
    def wrapper():
        print("在函数调用之前执行一些操作")
        func()  # 调用原始函数
        print("在函数调用之后执行一些操作")
    return wrapper
# 应用装饰器
@my_decorator
def say_hello():
    print("Hello, World!")
# 调用被装饰的函数
say_hello()
# 在函数调用之前执行一些操作
# Hello, World!
# 在函数调用之后执行一些操作
# [Finished in 625ms]

def log_decorator(func):
    def wrapper(*args, **kwargs):
        print(f"调用函数 {func.__name__}，参数: {args}, {kwargs}")
        result = func(*args, **kwargs)
        print(f"函数 {func.__name__} 执行完毕，结果: {result}")
        return result
    return wrapper
@log_decorator
def add(a, b):
    return a + b
result = add(2, 3)  #装饰器会记录函数的调用和结果
# 调用函数 add，参数: (2, 3), {}
# 函数 add 执行完毕，结果: 5
# [Finished in 578ms]

import time
def performance_decorator(func):
    def wrapper(*args, **kwargs):
        start_time = time.time()
        result = func(*args, **kwargs)
        end_time = time.time()
        print(f"函数 {func.__name__} 执行时间: {end_time - start_time} 秒")
        return result
    return wrapper
@performance_decorator
def slow_function():
    time.sleep(2)
slow_function()
# 函数 slow_function 执行时间: 2.0054738521575928 秒

class Person:
    total_people = 0
    def __init__(self, name):
        self.name = name
        Person.total_people += 1
    @classmethod
    def get_total_people(cls):
        return cls.total_people
p1 = Person("Alice")
p2 = Person("Bob")
total = Person.get_total_people()

class MathUtility:
    @staticmethod
    def add(a, b):
        return a + b
result = MathUtility.add(2, 3)