keys of kwargs must be the names passed to __init__(...) as `column_names`

def print_row(self, **kwargs):
        '''
        keys of kwargs must be the names passed to __init__(...) as `column_names`
        '''
        meta_string = '|'
        for key in self.column_names:
            float_specifier = ''
            if isinstance(kwargs[key], float):
                float_specifier = '.3f'
            meta_string += " {%s:<{width}%s}|" % (key, float_specifier)
        kwargs['width'] = self.column_width - 1

        print(meta_string.format(**kwargs))
        print(self.hr)