使用Elsevier API时如何获取Scopus每周剩余请求次数？

Great question—tracking your remaining Scopus API quota is super important to avoid hitting that weekly limit. Here's how to do it across the tools you're using:

1. Check Quota via API Response Headers #

The easiest way is to pull the quota details directly from the HTTP response headers that Elsevier returns with every API call. These headers include:

• X-RateLimit-Limit: Your total weekly request quota
• X-RateLimit-Remaining: The number of requests you have left this week
• X-RateLimit-Reset: A Unix timestamp indicating when your quota will reset

If you're making raw HTTP calls (or want to see the underlying data), here's a quick example with requests:

import requests

api_key = "YOUR_API_KEY"
endpoint = "https://api.elsevier.com/content/search/scopus?query=YOUR_SEARCH_QUERY"

headers = {"X-ELS-APIKey": api_key}
response = requests.get(endpoint, headers=headers)

# Extract quota info
total_quota = response.headers.get("X-RateLimit-Limit")
remaining_requests = response.headers.get("X-RateLimit-Remaining")
reset_timestamp = response.headers.get("X-RateLimit-Reset")

print(f"Total weekly quota: {total_quota}")
print(f"Remaining requests: {remaining_requests}")

2. Using the Official elsapy Module #

elsapy stores the last API response directly on the client object, so you can access the headers easily after any API call:

from elsapy.elsclient import ElsClient
from elsapy.elssearch import ElsSearch

# Initialize your client
client = ElsClient(api_key="YOUR_API_KEY")
# Add your institution token if you have one: client.inst_token = "YOUR_INST_TOKEN"

# Run a sample search to trigger a response
search = ElsSearch("TITLE(your research topic)", "scopus")
search.execute(client)

# Pull quota details from the last response
total_quota = client.last_response.headers.get("X-RateLimit-Limit")
remaining_requests = client.last_response.headers.get("X-RateLimit-Remaining")
reset_timestamp = client.last_response.headers.get("X-RateLimit-Reset")

print(f"You have {remaining_requests} requests left out of {total_quota} this week.")

3. Using the scopus-api Module #

Most Python Scopus modules expose the underlying HTTP response somewhere in their objects. For the scopus-api package, check if your search/query object has a _response or response attribute (this can vary by version):

from scopus import ScopusSearch

# Run a search
search = ScopusSearch("YOUR_QUERY", api_key="YOUR_API_KEY")

# Access the response headers
if hasattr(search, "_response"):
    remaining_requests = search._response.headers.get("X-RateLimit-Remaining")
    total_quota = search._response.headers.get("X-RateLimit-Limit")
    print(f"Remaining requests: {remaining_requests}/{total_quota}")

If _response doesn't work, check the module's documentation or inspect the object with dir(search) to find where the response is stored.

Bonus: Convert Reset Timestamp to Readable Time #

The X-RateLimit-Reset value is a Unix timestamp—convert it to a human-readable date with this snippet:

from datetime import datetime

reset_time = datetime.fromtimestamp(int(reset_timestamp))
print(f"Quota resets on: {reset_time.strftime('%Y-%m-%d %H:%M:%S')}")

Quick Notes #

• Institutional API keys often have higher quotas than personal ones—if you're hitting limits frequently, check with your university/library for an institutional token.
• If you get a 429 Too Many Requests error, you've exhausted your quota and need to wait for the reset or request a higher limit from Elsevier.

内容的提问来源于stack exchange，提问作者Lorcán