$ sudo apt-get install python-suds

from suds.client import Client
import logging

# Set logging to DEBUG so we can see the SOAP messages.
logging.basicConfig(level = logging.INFO)
logging.getLogger('suds.client').setLevel(logging.DEBUG)

# Specify Login Information
api_key = 'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx'
api_password = 'xxxxxxx'

# Specify URLs
wsdl_url = 'https://api.channeladvisor.com/ChannelAdvisorAPI/v5/InventoryService.asmx?WSDL'
service_url = 'https://api.channeladvisor.com/ChannelAdvisorAPI/v5/InventoryService.asmx'

# Initialize client.
client = Client(wsdl_url, location = service_url)

# Pass login information
login = client.factory.create('APICredentials')
login.DeveloperKey = api_key
login.Password = api_password
client.set_options(soapheaders=login)

# Initiate request
result = client.service.Ping()

# Print the result to the screen.
print result

<?php
$developer_key = 'xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx';
$password = 'xxxxxx';

$wsdl_url = 'https://api.channeladvisor.com/ChannelAdvisorAPI/v3/InventoryService.asmx?WSDL';
$api_url = 'http://api.channeladvisor.com/webservices/';

// Instantiate the client.
$client = new SoapClient($wsdl_url);

// Pass along login information
$soap_header = new SoapHeader(
	$api_url,
	'APICredentials',
	array(
		'DeveloperKey' => $developer_key,
		'Password' => $password
	)
);
$client->__setSoapHeaders($soap_header);

// Initiate the request.
$result = $client->Ping();

// Print the results.
print '<pre>';
var_export($result);
print '</pre>';