When scraping APIs, you're likely to encounter a range of HTTP status codes. These codes indicate the success or failure of an HTTP request. Here are some of the most common HTTP status codes you might encounter while web scraping:
2xx Success
- 200 OK: The request has succeeded, and the response contains the requested data.
- 201 Created: The request has been fulfilled and resulted in a new resource being created.
- 202 Accepted: The request has been accepted for processing, but the processing has not been completed.
- 204 No Content: The server successfully processed the request, but is not returning any content.
3xx Redirection
- 301 Moved Permanently: This and all future requests should be directed to the given URI.
- 302 Found: The server is redirecting to a different URL, which is often used in load balancing or A/B testing.
- 304 Not Modified: The resource has not been modified since the last request (often used in conjunction with caching).
4xx Client Errors
- 400 Bad Request: The server cannot or will not process the request due to something that is perceived as a client error (e.g., malformed request syntax).
- 401 Unauthorized: Authentication is required for the request, and it has not been provided or has failed.
- 403 Forbidden: The server understood the request but refuses to authorize it, often due to lack of permission.
- 404 Not Found: The requested resource could not be found on the server.
- 429 Too Many Requests: The user has sent too many requests in a given amount of time ("rate limiting").
5xx Server Errors
- 500 Internal Server Error: A generic error message indicating an unexpected condition on the server.
- 502 Bad Gateway: The server was acting as a gateway or proxy and received an invalid response from the upstream server.
- 503 Service Unavailable: The server is currently unable to handle the request due to temporary overloading or maintenance.
- 504 Gateway Timeout: The server was acting as a gateway or proxy and did not receive a timely response from the upstream server.
Handling HTTP Status Codes in Web Scraping
In web scraping, it's crucial to handle these HTTP status codes appropriately. Here is a simple example in Python using the requests library:
import requests
url = 'http://example.com/api/data'
response = requests.get(url)
if response.status_code == 200:
# Success! You can process the response data.
data = response.json()
elif response.status_code == 404:
# Resource not found; handle the error.
print('Resource not found.')
elif response.status_code == 429:
# Too many requests; you might want to implement a retry mechanism.
print('Rate limit exceeded. Try again later.')
else:
# Other errors; raise an exception or handle it as appropriate.
response.raise_for_status()
In JavaScript, using the fetch API might look like this:
fetch('http://example.com/api/data')
.then(response => {
if (!response.ok) {
throw new Error(`HTTP error! status: ${response.status}`);
}
return response.json();
})
.then(data => {
// Process your data here
console.log(data);
})
.catch(error => {
// Handle errors here
console.error('There was a problem with the fetch operation:', error);
});
Remember that when scraping APIs, you should respect the robots.txt file and terms of service of the website, as well as handle your requests in a way that does not harm the server (e.g., by obeying rate limits and using appropriate headers).
