Hi again and thanks for your reply @reddish,
actually, the offset that i meant is the channel offset (scope offset) not the analogimpedance offset just like what @JColvin said at 2nd paragraph. so, i use the analogIn.ChannelOffsetSet function.
And, so far your pydwf espescially the analogimpedance function working just fine at my project. so Thank you very much to make my work easier with your pydwf👍