code: def create_colspec(self, columns, overflow_default=None):
          
          spec = [{
              "width": None,
              "minwidth": self.column_minwidth,
              "padding": self.column_padding,
              "align": self.column_align,
              "overflow": self.overflow or overflow_default
          } for x in range(columns)]
          if self.columns_def:
              for dst, src in zip(spec, self.columns_def):
                  if hasattr(src, 'items'):
                      dst.update(src)
                  else:
                      dst['width'] = src
          return spec
docs: Produce a full format columns spec dictionary.  The overrides spec
          can be a partial columns spec as described in the __init__ method's
          depiction of the .columns attribute.