This example illustrates a common pattern for automatically refreshing an expired access token (like an OAuth2 token) when an API request fails with an authentication error.
Token Refresh Logic
The logic is as follows: make a request with the current token. If it fails with a `401 Unauthorized` error, attempt to get a new token using a refresh token. If the refresh is successful, retry the original request with the new token.
import requests
# --- Store your tokens (in a real app, this would be more secure) ---
ACCESS_TOKEN = "expired_or_invalid_token"
REFRESH_TOKEN = "valid_refresh_token"
TOKEN_URL = "https://your-auth-server.com/oauth/token"
def refresh_access_token():
"""Simulates refreshing the access token."""
print("Attempting to refresh the access token...")
# In a real implementation:
# payload = {'grant_type': 'refresh_token', 'refresh_token': REFRESH_TOKEN}
# response = requests.post(TOKEN_URL, data=payload)
# response.raise_for_status()
# new_token = response.json()['access_token']
# return new_token
# For this example, we'll just return a new dummy token.
new_token = "new_shiny_access_token"
print("Token refreshed successfully.")
return new_token
def get_protected_data():
global ACCESS_TOKEN
url = "https://my-api.com/data"
headers = {'Authorization': f'Bearer {ACCESS_TOKEN}'}
# --- This part would be a real API call ---
# response = requests.get(url, headers=headers)
# --- We simulate a 401 response initially ---
print(f"Making request with token: {ACCESS_TOKEN}")
response_status_code = 401 # Simulate failure
if response_status_code == 401:
print("Access token expired or invalid (401).")
try:
ACCESS_TOKEN = refresh_access_token()
headers['Authorization'] = f'Bearer {ACCESS_TOKEN}'
# --- Retry the request with the new token ---
print(f"Retrying request with new token: {ACCESS_TOKEN}")
# response = requests.get(url, headers=headers)
# response.raise_for_status()
# --- Simulate success on the retry ---
print("Request successful on retry!")
return {"data": "super secret data"}
except Exception as e:
print(f"Failed to refresh token or retry request: {e}")
return None
get_protected_data()
