python 缓存函数结果，下次不会执行函数时直接获取结果[ lru_cache 、cache]

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from functools import lru_cache

from pydantic import BaseSettings
n = 0

class Settings(BaseSettings):
    environment: str = "development"

@lru_cache(maxsize=128, typed=False)  # 被 lru_cache 修饰的函数在被相同参数调用的时候，后续的调用都是直接从缓存读结果，而不用真正执行函数。
def get_settings():  # 如果调用两次传的参数不一样，无法缓存
    global n
    settings = Settings()
    print(f"Loaded settings for environment: {settings.environment}")
    n += 1
    return settings

def action_a():
    print(get_settings().environment)

def action_b():
    print(get_settings().environment)



if __name__ == "__main__":
    action_a()
    action_b()
    print(n)

输出：

Loaded settings for environment: development
development
development
1

可以看出函数调用了两次，但是n只增加了一次。去掉lru_cache装饰器，n就是2了