human
Complete the below
def launch(address='127.0.0.1', port=6633, max_retry_delay=16, dpid=None, ports='', extra=None, ctl_port=None, __INSTANCE__=None):

    ''''Launches a switch'
    '''

=====
Can you provide a the Python code you requested?
assistant
#Here is the Python code you requested.
    if (not pxpcap.enabled):
        raise RuntimeError('You    need    PXPCap    to    use    this    component')
    if ctl_port:
        if core.hasComponent('ctld'):
            raise RuntimeError('Only    one    ctl_port    is    allowed')
        if (ctl_port is True):
            ctl_port = DEFAULT_CTL_PORT
        import ctl
        ctl.server(ctl_port)
        core.ctld.addListenerByName('CommandEvent', _do_ctl)
    _ports = ports.strip()
    def up(event):
        ports = [p for p in _ports.split(',') if p]
        sw = do_launch(PCapSwitch, address, port, max_retry_delay, dpid, ports=ports, extra_args=extra)
        _switches[sw.name] = sw
    core.addListenerByName('UpEvent', up)