name : opensocketexception.py # Exposing rich exception information from callbacks example import pycurl, random, socket class ConnectionRejected(Exception): pass def opensocket(curl, purpose, curl_address): if random.random() < 0.5: curl.exception = ConnectionRejected('Rejecting connection attempt in opensocket callback') return pycurl.SOCKET_BAD family, socktype, protocol, address = curl_address s = socket.socket(family, socktype, protocol) s.setsockopt(socket.SOL_SOCKET, socket.SO_KEEPALIVE, 1) return s c = pycurl.Curl() c.setopt(c.URL, 'http://pycurl.io') c.exception = None c.setopt(c.OPENSOCKETFUNCTION, lambda purpose, address: opensocket(c, purpose, address)) try: c.perform() except pycurl.error as e: if e.args[0] == pycurl.E_COULDNT_CONNECT and c.exception: print(c.exception) else: print(e)