将预定功能导入另一个文件 python

Question

I am making a tool to post-registration information to an API, using python. I'm having a problem with the token expiring. The token's expiration time is 300 seconds, so I have to constantly refresh the token. Is there any way I can schedule a token refresh after 300 seconds?

I have a python script in a file called logAPI.py containing multiple tasks, processes and functions (and it works). I have another file called authorization.py containing a function that calls to authorization API and returns a token so I can call other APIs. Since the token expires time is 300 seconds, I intend to return a new token after 300 seconds.

I tried while function, schedule module, cron module and import os but I failed with all.

Answer 1

I think this is the most straightforward solution you can do without having a separate thread to refresh the token.

AuthToken contains the active token as well as the logic needed to refresh it. When you need a token, you call AuthToken.get() . This fetches a new token if it's the first time it's being called, or if the token has expired. When the new token is fetched, it's stored in the _auth_token singleton. This caches it for later and also lets us know when it's expired.

It sounds like you're using multithreading, so I added a Lock to prevent a race condition when calling AuthToken.get()

It's important that you always call AuthToken.get() before making a request. Even just making two requests back-to-back, there's a possibility the token might expire before the second request is sent.

You may also want to adjust the TTL to be slightly lower in case there's latency making the request.

import requests
import time

from threading import Lock
from typing import Optional
from typing_extensions import Self


class AuthToken:
    """Represents an auth token used by the API."""

    # A singleton AuthToken instance
    _auth_token: Optional[Self] = None
    _lock = Lock()

    # The token's TTL (in seconds)
    ttl = 300

    expires: int
    token: str

    def __init__(self, token):
        self.token = token
        self.expires = time.time() + self.ttl

    def is_expired(self):
        """Returns True if the token is expired."""
        return time.time() >= self.expires

    @classmethod
    def get(cls) -> Self:
        """Returns a valid auth token, refreshing the current one if it's expired."""
        cls._lock.acquire()

        if not cls._auth_token or cls._auth_token.is_expired():
            # do API request...
            token = "foo"
            cls._auth_token = AuthToken(token)

        cls._lock.release()

        return cls._auth_token


def request_that_needs_token():
    auth = AuthToken.get()

    # use auth.token in your request
    requests.post(
        "http://example.com", headers={"Authorization": f"Bearer {auth.token}"}
    )