I think for some builtins it may be usefull to have keyword arguments, in the case they take more than one parameter.

Typically, it's impossible to write:

    self.drop_elements(partial(isinstance, type(lxml.etree.Comment)))

Because isinstance take its argument in the "other" order, we may bypass this using keywords arguments:


    self.drop_elements(partial(isinstance, type=type(lxml.etree.Comment)))

But isinstance refuses keyword arguments, so there is no way to write this without a lambda:

    self.drop_elements(lambda x: isinstance(x,
                       type(lxml.etree.Comment)))

With is cool and work, I agree, it's just an example to explicitly show why keywords argument may be cool: functools.partial.