'Handling a timeout error in Python sockets

I am trying to figure out how to use the try and except to handle a socket timeout.

from socket import *

def main():
    client_socket = socket(AF_INET,SOCK_DGRAM)
    client_socket.settimeout(1)
    server_host = 'localhost'
    server_port = 1234
    while(True):
        client_socket.sendto('Message',(server_host,server_port))
        try:
            reply, server_address_info = client_socket.recvfrom(1024)
            print reply
        except socket.Timeouterror:
            # More code

The way I added the socket module was to import everything, but how do I handle exceptions?

In the documentation it says you can use socket.timeouterror, but that doesn't work for me. Also, how would I write the try exception block if I did import socket? What is the difference in the imports?

Solution 1:^[1]

I had enough success just catching socket.timeout and socket.error; although socket.error can be raised for lots of reasons. Be careful.

import socket
import logging

hostname = 'google.com'
port = 443

try:
    sock = socket.create_connection((hostname, port), timeout=3)

except socket.timeout as err:
    logging.error(err)

except socket.error as err:
    logging.error(err)

Solution 2:^[2]

When you do from socket import *, the Python interpreter is loading a socket module to the current namespace. Thus you can use the module's members as if they were defined within your current Python module.

When you do import socket, a module is loaded in a separate namespace. When you are accessing its members, you should prefix them with a module name. For example, if you want to refer to a socket class, you will need to write client_socket = socket.socket(socket.AF_INET,socket.SOCK_DGRAM).

As for the problem with timeout, all you need to do is to change except socket.Timeouterror: to except timeout:, since timeout class is defined inside socket module and you have imported all its members to your namespace.

Solution 3:^[3]

Here is a solution I use in one of my projects.

File network_utils.telnet

import socket
from timeit import default_timer as timer

def telnet(hostname, port=23, timeout=1):
    start = timer()
    connection = socket.socket()
    connection.settimeout(timeout)
    try:
        connection.connect((hostname, port))
        end = timer()
        delta = end - start
    except (socket.timeout, socket.gaierror) as error:
        logger.debug('telnet error: ', error)
        delta = None
    finally:
        connection.close()

    return {
        hostname: delta
    }

Tests

def test_telnet_is_null_when_host_unreachable(self):
    hostname = 'unreachable'

    response = network_utils.telnet(hostname)

    self.assertDictEqual(response, {'unreachable': None})

def test_telnet_give_time_when_reachable(self):
    hostname = '127.0.0.1'

    response = network_utils.telnet(hostname, port=22)

    self.assertGreater(response[hostname], 0)

Sources

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Source: Stack Overflow

Solution	Source
Solution 1	Peter Mortensen
Solution 2	Peter Mortensen
Solution 3	Peter Mortensen

'Handling a timeout error in Python sockets

Solution 1:[1]

Solution 2:[2]

Solution 3:[3]