geventhttpclient

Warnings

• gotcha gevent's `monkey.patch_all()` is essential. If not called, `geventhttpclient` will perform blocking I/O operations, defeating the purpose of gevent.
  Fix: Ensure `from gevent import monkey; monkey.patch_all()` is called at the very beginning of your application's lifecycle, before any blocking I/O is performed.
• gotcha Always close `HTTPClient` instances explicitly (`client.close()`) or use them as context managers (`with HTTPClient(...) as client:`). Failing to do so can lead to connection leaks and resource exhaustion, especially when using connection pooling.
  Fix: Surround client usage with a `try...finally` block calling `client.close()` or use a `with` statement: `with HTTPClient.from_url(...) as client: ...`
• gotcha By default, `geventhttpclient` does not raise exceptions for HTTP error status codes (e.g., 4xx, 5xx). You must explicitly check `response.status` or configure the client to raise exceptions.
  Fix: Check `response.status` after every request: `if not 200 <= response.status < 300: # handle error`. Alternatively, set `raise_request_exception=True` when initializing the client or on the request call: `client.get('/path', raise_request_exception=True)`.
• gotcha Reading the entire response body with `response.read()` loads it into memory. For very large responses, this can consume significant memory.
  Fix: For large responses, read the body in chunks using `response.read(chunk_size)` or iterate over the response object if it supports chunked reading to process data incrementally.

Install

• pip install geventhttpclient Install stable version

Imports

• HTTPClient

  from geventhttpclient import HTTPClient

• HTTPClientPool

  from geventhttpclient.pool import HTTPClientPool

• response

  from geventhttpclient import response

Quickstart

This quickstart demonstrates how to initialize gevent's monkey patching, create an `HTTPClient` instance, perform a GET request, and handle the response. It highlights the importance of `monkey.patch_all()` and proper client closure.

import gevent
from geventhttpclient import HTTPClient
from gevent import monkey
import logging

# Crucial for gevent to work properly
monkey.patch_all()

# Optional: Set up basic logging to see gevent events if needed
# logging.basicConfig(level=logging.INFO)

def fetch_url(url):
    # Create a client instance for a specific host
    # Using httpbin.org for a public, testable endpoint
    client = HTTPClient.from_url(url, 
                                 connection_timeout=5, 
                                 network_timeout=10)
    try:
        # Make a GET request to a path relative to the client's base URL
        resp = client.get('/get?foo=bar')
        
        print(f"Requested: {url}/get?foo=bar")
        print(f"Status: {resp.status}")
        print(f"Headers: {resp.headers['Content-Type']}")
        
        # Read the response body. For large responses, consider resp.read(chunk_size)
        body = resp.read()
        print(f"Body snippet: {body[:100]}...")

    except Exception as e:
        print(f"Error fetching {url}: {e}")
    finally:
        # Always close the client to release resources, especially connection pool
        client.close()

if __name__ == '__main__':
    # Spawn a greenlet to run the network operation non-blocking
    greenlet = gevent.spawn(fetch_url, 'http://httpbin.org')
    # Wait for the greenlet to complete
    greenlet.join()