human
Here's a good function header given the following:
I wrote the below code

    def check_dim(dim, name):
        if (not isinstance(dim, (tuple, list))):
            dim = [dim]
        else:
            dim = list(dim)
        if (len(dim) > 3):
            raise ValueError(('%s    must    be    a    sequence    of    1,    2    or    3    integers,    got    %r' % (name, dim)))
        for v in dim:
            if (not isinstance(v, numbers.Integral)):
                raise TypeError(('%s    must    be    a    sequence    of    integers,    got    %r' % (name, dim)))
        while (len(dim) < 3):
            dim.append(1)
        return dim
    griddim = check_dim(griddim, 'griddim')
    blockdim = check_dim(blockdim, 'blockdim')
    return (griddim, blockdim)

What's a good function header?
assistant
#Here's a good function header.

def normalize_kernel_dimensions(griddim, blockdim):