How to write an elegant Python setting class default value

There is a need to set a default value for a class today

The first code is as follows:

Class myClass     def __init__ (self,datalen=none,times=None):         if datalen = = None            := 1024x768        else  :            = datalen             if times = = None            := 1024*1024        else  :            = times

But this is too not python, simple modification as follows, is not looking much better?

    def __init__ (self,datalen=none,times=None):         if  is  not Else 1024x768                ifis notelse 1024*1024

How to write an elegant Python setting class default value