Example usage of getting a handle to a vSphere session and retrieving all the ESX hosts in a server:

from oslo_vmware import api
from oslo_vmware import vim_util

# Get a handle to a vSphere API session
session = api.VMwareAPISession(
    '',      # vSphere host endpoint
    'administrator', # vSphere username
    'password',      # vSphere password
    10,              # Number of retries for connection failures in tasks
    0.1              # Poll interval for async tasks (in seconds)

# Example call to get all the managed objects of type "HostSystem"
# on the server.
result = session.invoke_api(
    vim_util,                           # Handle to VIM utility module
    'get_objects',                      # API method name to invoke
    session.vim, 'HostSystem', 100)     # Params to API method (*args)